diff --git a/src/components/user_config/user_config.cpp b/src/components/user_config/user_config.cpp
index 42d0aef1..d930491e 100644
--- a/src/components/user_config/user_config.cpp
+++ b/src/components/user_config/user_config.cpp
@@ -13,8 +13,15 @@ std::string get_xdg_user_config_home()
     std::string home(getenv("HOME"));
     path = home + "/Library/Application Support";
 #elif _WIN32
+#if __STDC_WANT_SECURE_LIB__
+    char *app_data_env = NULL;
+    size_t app_data_env_sz = 0;
+    _dupenv_s(&app_data_env, &app_data_env_sz, "LOCALAPPDATA");
+    if (!app_data_env) _dupenv_s(&app_data_env, &app_data_env_sz, "APPDATA");
+#else
     char *app_data_env = getenv("LOCALAPPDATA");
     if (!app_data_env) app_data_env = getenv("APPDATA");
+#endif
     std::string app_data(app_data_env);
     path = app_data;
 #else // Unix
@@ -40,8 +47,15 @@ std::string get_xdg_user_data_home()
     std::string home(getenv("HOME"));
     path = home + "/Library/Application Support";
 #elif _WIN32
+#if __STDC_WANT_SECURE_LIB__
+    char *app_data_env = NULL;
+    size_t app_data_env_sz = 0;
+    _dupenv_s(&app_data_env, &app_data_env_sz, "LOCALAPPDATA");
+    if (!app_data_env) _dupenv_s(&app_data_env, &app_data_env_sz, "APPDATA");
+#else
     char *app_data_env = getenv("LOCALAPPDATA");
     if (!app_data_env) app_data_env = getenv("APPDATA");
+#endif
     std::string app_data(app_data_env);
     path = app_data;
 #else // Unix
diff --git a/src/core/base/file_util.h b/src/core/base/file_util.h
index 34ca4a6a..ba32aca8 100644
--- a/src/core/base/file_util.h
+++ b/src/core/base/file_util.h
@@ -40,7 +40,7 @@ void utilReadDataMem(const uint8_t *&data, variable_desc *);
 #else  // !defined(__LIBRETRO__)
 
 // strip .gz or .z off end
-void utilStripDoubleExtension(const char *, char *);
+void utilStripDoubleExtension(const char *, char *, size_t);
 
 gzFile utilAutoGzOpen(const char *file, const char *mode);
 gzFile utilGzOpen(const char *file, const char *mode);
diff --git a/src/core/base/file_util_common.cpp b/src/core/base/file_util_common.cpp
index 36d749a4..eade5ad8 100644
--- a/src/core/base/file_util_common.cpp
+++ b/src/core/base/file_util_common.cpp
@@ -27,7 +27,13 @@ FILE* utilOpenFile(const char* filename, const char* mode) {
         return nullptr;
     }
 
+#if __STDC_WANT_SECURE_LIB__
+    FILE *ret = NULL;
+    _wfopen_s(&ret, wfilename.data(), wmode.data());
+    return ret;
+#else
     return _wfopen(wfilename.data(), wmode.data());
+#endif
 #else
     return fopen(filename, mode);
 #endif  // _WIN32
diff --git a/src/core/base/file_util_desktop.cpp b/src/core/base/file_util_desktop.cpp
index 6f9c366d..9229e2cb 100644
--- a/src/core/base/file_util_desktop.cpp
+++ b/src/core/base/file_util_desktop.cpp
@@ -48,10 +48,15 @@ fex_t* scanArchive(const char* file, bool (*accept)(const char*), char (&buffer)
     // Scan filenames
     bool found = false;
     while (!fex_done(fe)) {
+#ifdef __STDC_WANT_SECURE_LIB__
+        strncpy_s(buffer, sizeof buffer, fex_name(fe), sizeof buffer);
+#else
         strncpy(buffer, fex_name(fe), sizeof buffer);
+#endif
+
         buffer[sizeof buffer - 1] = '\0';
 
-        utilStripDoubleExtension(buffer, buffer);
+        utilStripDoubleExtension(buffer, buffer, sizeof buffer);
 
         if (accept(buffer)) {
             found = true;
@@ -153,9 +158,16 @@ IMAGE_TYPE utilFindType(const char* file) {
     return utilFindType(file, buffer);
 }
 
-void utilStripDoubleExtension(const char* file, char* buffer) {
+void utilStripDoubleExtension(const char* file, char* buffer, size_t len) {
+#if !__STDC_WANT_SECURE_LIB__
+    (void)len;
+#endif
     if (buffer != file)  // allows conversion in place
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(buffer, len, file);
+#else
         strcpy(buffer, file);
+#endif
 
     if (utilIsGzipFile(file)) {
         char* p = strrchr(buffer, '.');
diff --git a/src/core/base/image_util.cpp b/src/core/base/image_util.cpp
index ce6c8edd..bf018c59 100644
--- a/src/core/base/image_util.cpp
+++ b/src/core/base/image_util.cpp
@@ -100,7 +100,12 @@ bool utilWritePNGFile(const char* fileName, int w, int h, uint8_t* pix) {
 bool utilWriteBMPFile(const char* fileName, int w, int h, uint8_t* pix) {
     uint8_t writeBuffer[512 * 3];
 
+#if __STDC_WANT_SECURE_LIB__
+    FILE* fp = NULL;
+    fopen_s(&fp, fileName, "wb");
+#else
     FILE* fp = fopen(fileName, "wb");
+#endif
 
     if (!fp) {
         systemMessage(MSG_ERROR_CREATING_FILE, N_("Error creating file %s"), fileName);
diff --git a/src/core/fex/fex/Data_Reader.cpp b/src/core/fex/fex/Data_Reader.cpp
index c65bcbb7..ed96b802 100644
--- a/src/core/fex/fex/Data_Reader.cpp
+++ b/src/core/fex/fex/Data_Reader.cpp
@@ -518,7 +518,11 @@ static FILE* blargg_fopen( const char path [], const char mode [] )
 	{
 		wmode = blargg_to_wide( mode );
 		if ( wmode )
+#if __STDC_WANT_SECURE_LIB__
+			_wfopen_s(&file, wpath, wmode );
+#else                        
 			file = _wfopen( wpath, wmode );
+#endif
 	}
 	
 	// Save and restore errno in case free() clears it
diff --git a/src/core/fex/fex/Zip7_Extractor.cpp b/src/core/fex/fex/Zip7_Extractor.cpp
index 831ec3b1..a4b9f181 100644
--- a/src/core/fex/fex/Zip7_Extractor.cpp
+++ b/src/core/fex/fex/Zip7_Extractor.cpp
@@ -288,7 +288,11 @@ blargg_err_t Zip7_Extractor::next_v()
 				time_t _time = time;
 				
 			#ifdef _WIN32
-				tm = *localtime( &_time );
+				#if __STDC_WANT_SECURE_LIB__
+					localtime_s(&tm, &_time);
+				#else
+					tm = *localtime( &_time );
+				#endif
 			#else
 				localtime_r( &_time, &tm );
 			#endif
diff --git a/src/core/gb/gb.cpp b/src/core/gb/gb.cpp
index 893c79d4..cf73b588 100644
--- a/src/core/gb/gb.cpp
+++ b/src/core/gb/gb.cpp
@@ -66,7 +66,11 @@ std::vector<VBamIoVec> g_vbamIoVecs;
 void ResetMBC3RTC() {
     time(&gbDataMBC3.mapperLastTime);
     struct tm* lt;
+#if __STDC_WANT_SECURE_LIB__
+    localtime_s(lt, &gbDataMBC3.mapperLastTime);
+#else
     lt = localtime(&gbDataMBC3.mapperLastTime);
+#endif
     gbDataMBC3.mapperSeconds = lt->tm_sec;
     gbDataMBC3.mapperMinutes = lt->tm_min;
     gbDataMBC3.mapperHours = lt->tm_hour;
@@ -80,7 +84,11 @@ void ResetTama5RTC() {
                                  31, 31, 30, 31, 30, 31};
     time(&gbDataTAMA5.mapperLastTime);
     struct tm* lt;
+#if __STDC_WANT_SECURE_LIB__
+    localtime_s(lt, &gbDataTAMA5.mapperLastTime);
+#else
     lt = localtime(&gbDataTAMA5.mapperLastTime);
+#endif
     gbDataTAMA5.mapperSeconds = lt->tm_sec;
     gbDataTAMA5.mapperMinutes = lt->tm_min;
     gbDataTAMA5.mapperHours = lt->tm_hour;
@@ -111,7 +119,12 @@ void ResetTama5RTC() {
 
 void ResetHuc3RTC() {
     time(&gbRTCHuC3.mapperLastTime);
+#if __STDC_WANT_SECURE_LIB__
+    struct tm* lt;
+    localtime_s(lt, &gbRTCHuC3.mapperLastTime);
+#else
     localtime(&gbRTCHuC3.mapperLastTime);
+#endif
 }
 
 bool WriteBatteryFile(const char* file_name) {
diff --git a/src/core/gb/gbCheats.cpp b/src/core/gb/gbCheats.cpp
index 1cd31ec0..6f48e2c4 100644
--- a/src/core/gb/gbCheats.cpp
+++ b/src/core/gb/gbCheats.cpp
@@ -209,8 +209,13 @@ bool gbAddGsCheat(const char* code, const char* desc)
 
     int i = gbCheatNumber;
 
+#if __STDC_WANT_SECURE_LIB__
+    strcpy_s(gbCheatList[i].cheatCode, sizeof(gbCheatList[i].cheatCode), code);
+    strcpy_s(gbCheatList[i].cheatDesc, sizeof(gbCheatList[i].cheatDesc), desc);
+#else
     strcpy(gbCheatList[i].cheatCode, code);
     strcpy(gbCheatList[i].cheatDesc, desc);
+#endif
 
     gbCheatList[i].code = GBCHEAT_HEX_VALUE(code[0]) << 4 | GBCHEAT_HEX_VALUE(code[1]);
 
@@ -318,8 +323,13 @@ bool gbAddGgCheat(const char* code, const char* desc)
 
     size_t len = strlen(code);
 
+#if __STDC_WANT_SECURE_LIB__
+    strcpy_s(gbCheatList[i].cheatCode, sizeof(gbCheatList[i].cheatCode), code);
+    strcpy_s(gbCheatList[i].cheatDesc, sizeof(gbCheatList[i].cheatDesc), desc);
+#else
     strcpy(gbCheatList[i].cheatCode, code);
     strcpy(gbCheatList[i].cheatDesc, desc);
+#endif
 
     gbCheatList[i].code = 0x101;
     gbCheatList[i].value = (GBCHEAT_HEX_VALUE(code[0]) << 4) + GBCHEAT_HEX_VALUE(code[1]);
diff --git a/src/core/gba/debugger-expr-lex.cpp b/src/core/gba/debugger-expr-lex.cpp
index 8b0bbfe0..c1665567 100644
--- a/src/core/gba/debugger-expr-lex.cpp
+++ b/src/core/gba/debugger-expr-lex.cpp
@@ -899,6 +899,10 @@ static int input ( void );
 
 #endif
 
+#if __STDC_WANT_SECURE_LIB__
+#define sscanf sscanf_s
+#endif
+
 /* No semi-colon after return; correct usage is to write "yyterminate();" -
  * we don't want an extra ';' after the "return" because that will cause
  * some compilers to complain about unreachable statements.
diff --git a/src/core/gba/debugger-expr-yacc.cpp b/src/core/gba/debugger-expr-yacc.cpp
index 4028be39..f6863d10 100644
--- a/src/core/gba/debugger-expr-yacc.cpp
+++ b/src/core/gba/debugger-expr-yacc.cpp
@@ -1516,7 +1516,12 @@ void dexp_saveVars(char *file)
 {
   std::map<std::string, uint32_t>::iterator iter;
 
+#if __STDC_WANT_SECURE_LIB__
+  FILE* f = NULL;
+  fopen_s(&f, file, "w");
+#else
   FILE *f = fopen(file, "w");
+#endif
   if (!f) {
     printf("Could not open file %s\n", file);
     return;
@@ -1535,14 +1540,23 @@ void dexp_loadVars(char *file)
   char name[500];
   uint32_t val;
 
+#if __STDC_WANT_SECURE_LIB__
+  FILE* f = NULL;
+  fopen_s(&f, file, "r");
+#else
   FILE *f = fopen(file, "r");
+#endif
   if (!f) {
     printf("Could not open file %s\n", file);
     return;
   }
 
   while (fgets(buffer, 500, f) != NULL) {
-    if (sscanf(buffer, "%s = %x",name,&val) == 2) {
+#if __STDC_WANT_SECURE_LIB__
+    if (sscanf_s(buffer, "%s = %x", name, (unsigned)_countof(name), &val) == 2) {
+#else
+    if (sscanf(buffer, "%s = %x", name, &val) == 2) {
+#endif
       dexp_setVar(name, val);
     }
   }
diff --git a/src/core/gba/gbaCheats.cpp b/src/core/gba/gbaCheats.cpp
index 10ec2764..cc8854b5 100644
--- a/src/core/gba/gbaCheats.cpp
+++ b/src/core/gba/gbaCheats.cpp
@@ -11,6 +11,7 @@
 
 #if __STDC_WANT_SECURE_LIB__
 #define snprintf sprintf_s
+#define sscanf sscanf_s
 #endif
 
 /**
@@ -1299,8 +1300,13 @@ void cheatsAdd(const char* codeStr,
         cheatsList[x].rawaddress = rawaddress;
         cheatsList[x].address = address;
         cheatsList[x].value = value;
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(cheatsList[x].codestring, sizeof(cheatsList[x].codestring), codeStr);
+        strcpy_s(cheatsList[x].desc, sizeof(cheatsList[x].desc), desc);
+#else
         strcpy(cheatsList[x].codestring, codeStr);
         strcpy(cheatsList[x].desc, desc);
+#endif
         cheatsList[x].enabled = true;
         cheatsList[x].status = 0;
 
@@ -1461,7 +1467,11 @@ bool cheatsVerifyCheatCode(const char* code, const char* desc)
     uint32_t value = 0;
 
     char buffer[10];
+#if __STDC_WANT_SECURE_LIB__
+    strncpy_s(buffer, sizeof(buffer), code, 8);
+#else
     strncpy(buffer, code, 8);
+#endif
     buffer[8] = 0;
     sscanf(buffer, "%x", &address);
 
@@ -1486,7 +1496,12 @@ bool cheatsVerifyCheatCode(const char* code, const char* desc)
         return false;
     }
 
+#if __STDC_WANT_SECURE_LIB__
+    strncpy_s(buffer, sizeof(buffer), &code[9], 8);
+#else
     strncpy(buffer, &code[9], 8);
+#endif
+
     sscanf(buffer, "%x", &value);
     int type = 0;
     if (len == 13)
@@ -1574,11 +1589,19 @@ void cheatsAddGSACode(const char* code, const char* desc, bool v3)
     }
 
     char buffer[10];
+#if __STDC_WANT_SECURE_LIB__
+    strncpy_s(buffer, sizeof(buffer), code, 8);
+#else
     strncpy(buffer, code, 8);
+#endif
     buffer[8] = 0;
     uint32_t address;
     sscanf(buffer, "%x", &address);
+#if __STDC_WANT_SECURE_LIB__
+    strncpy_s(buffer, sizeof(buffer), &code[8], 8);
+#else
     strncpy(buffer, &code[8], 8);
+#endif
     buffer[8] = 0;
     uint32_t value;
     sscanf(buffer, "%x", &value);
@@ -2459,11 +2482,19 @@ void cheatsAddCBACode(const char* code, const char* desc)
     }
 
     char buffer[10];
+#if __STDC_WANT_SECURE_LIB__
+    strncpy_s(buffer, sizeof(buffer), code, 8);
+#else
     strncpy(buffer, code, 8);
+#endif
     buffer[8] = 0;
     uint32_t address;
     sscanf(buffer, "%x", &address);
+#if __STDC_WANT_SECURE_LIB__
+    strncpy_s(buffer, sizeof(buffer), &code[9], 4);
+#else
     strncpy(buffer, &code[9], 4);
+#endif
     buffer[4] = 0;
     uint32_t value;
     sscanf(buffer, "%x", &value);
@@ -2640,12 +2671,20 @@ void cheatsReadGame(gzFile file, int version)
         if (cheatsList[i].code == 512 && firstCodeBreaker) {
             firstCodeBreaker = false;
             char buffer[10];
+#if __STDC_WANT_SECURE_LIB__
+            strncpy_s(buffer, sizeof(buffer), cheatsList[i].codestring, 8);
+#else
             strncpy(buffer, cheatsList[i].codestring, 8);
+#endif
             buffer[8] = 0;
             uint32_t address;
             sscanf(buffer, "%x", &address);
             if ((address >> 28) == 9) {
+#if __STDC_WANT_SECURE_LIB__
+                strncpy_s(buffer, sizeof(buffer), &cheatsList[i].codestring[9], 4);
+#else
                 strncpy(buffer, &cheatsList[i].codestring[9], 4);
+#endif
                 buffer[4] = 0;
                 uint32_t value;
                 sscanf(buffer, "%x", &value);
@@ -2780,12 +2819,20 @@ bool cheatsLoadCheatList(const char* file)
         if (cheatsList[i].code == 512 && firstCodeBreaker) {
             firstCodeBreaker = false;
             char buffer[10];
+#if __STDC_WANT_SECURE_LIB__
+            strncpy_s(buffer, sizeof(buffer), cheatsList[i].codestring, 8);
+#else
             strncpy(buffer, cheatsList[i].codestring, 8);
+#endif
             buffer[8] = 0;
             uint32_t address;
             sscanf(buffer, "%x", &address);
             if ((address >> 28) == 9) {
+#if __STDC_WANT_SECURE_LIB__
+                strncpy_s(buffer, sizeof(buffer), &cheatsList[i].codestring[9], 4);
+#else
                 strncpy(buffer, &cheatsList[i].codestring[9], 4);
+#endif
                 buffer[4] = 0;
                 uint32_t value;
                 sscanf(buffer, "%x", &value);
diff --git a/src/core/gba/gbaCpuThumb.cpp b/src/core/gba/gbaCpuThumb.cpp
index c1ba0c2d..10e84290 100644
--- a/src/core/gba/gbaCpuThumb.cpp
+++ b/src/core/gba/gbaCpuThumb.cpp
@@ -20,8 +20,12 @@
 #endif
 
 #ifdef _MSC_VER
+#if __STDC_WANT_SECURE_LIB__
+#define snprintf sprintf_s
+#else
 #define snprintf _snprintf
 #endif
+#endif
 
 ///////////////////////////////////////////////////////////////////////////
 
diff --git a/src/core/gba/gbaElf.cpp b/src/core/gba/gbaElf.cpp
index 044901d7..59305be4 100644
--- a/src/core/gba/gbaElf.cpp
+++ b/src/core/gba/gbaElf.cpp
@@ -280,7 +280,11 @@ const char* elfGetAddressSymbol(uint32_t addr)
                 if (offset)
                     snprintf(buffer, 256, "%s+%d", name, offset);
                 else {
+#if __STDC_WANT_SECURE_LIB__
+                    strncpy_s(buffer, sizeof(buffer), name, 255); //strncpy_s does not allways append a '\0'
+#else
                     strncpy(buffer, name, 255);		//strncpy does not allways append a '\0'
+#endif
 		    buffer[255] = '\0';
 		}
                 return buffer;
@@ -300,16 +304,28 @@ const char* elfGetAddressSymbol(uint32_t addr)
                 if (offset)
                     snprintf(buffer, 256,"%s+%d", name, addr - s->value);
                 else {
+#if __STDC_WANT_SECURE_LIB__
+                    strncpy_s(buffer, sizeof(buffer), name, 255);
+#else
                     strncpy(buffer, name, 255);
+#endif
 		    buffer[255] = '\0';
 		}
                 return buffer;
             } else if (addr == s->value) {
                 if (s->name) {
+#if __STDC_WANT_SECURE_LIB__
+                    strncpy_s(buffer, sizeof(buffer), s->name, 255);
+#else
                     strncpy(buffer, s->name, 255);
+#endif
 		    buffer[255] = '\0';
 		} else
+#if __STDC_WANT_SECURE_LIB__
+                    strcpy_s(buffer, sizeof(buffer), "");
+#else
                     strcpy(buffer, "");
+#endif
                 return buffer;
             }
         }
diff --git a/src/core/gba/gbaLink.cpp b/src/core/gba/gbaLink.cpp
index 4bb45a51..c35f1855 100644
--- a/src/core/gba/gbaLink.cpp
+++ b/src/core/gba/gbaLink.cpp
@@ -538,21 +538,37 @@ bool GetLinkServerHost(char* const host, size_t size)
     host[0] = '\0';
 
     if (linkDriver && linkDriver->mode == LINK_GAMECUBE_DOLPHIN) {
+#if __STDC_WANT_SECURE_LIB__
+        strncpy_s(host, size, joybusHostAddr.toString().c_str(), size);
+#else
         strncpy(host, joybusHostAddr.toString().c_str(), size);
+#endif
     } else if (lanlink.server) {
         if (IP_LINK_BIND_ADDRESS == "*") {
             auto local_addr = sf::IpAddress::getLocalAddress();
             if (local_addr) {
+#if __STDC_WANT_SECURE_LIB__
+                strncpy_s(host, size, local_addr.value().toString().c_str(), size);
+#else
                 strncpy(host, local_addr.value().toString().c_str(), size);
+#endif
             } else {
                 return false;
             }
         } else {
+#if __STDC_WANT_SECURE_LIB__
+            strncpy_s(host, size, IP_LINK_BIND_ADDRESS.c_str(), size);
+#else
             strncpy(host, IP_LINK_BIND_ADDRESS.c_str(), size);
+#endif
         }
     }
     else {
+#if __STDC_WANT_SECURE_LIB__
+        strncpy_s(host, size, lc.serveraddr.toString().c_str(), size);
+#else
         strncpy(host, lc.serveraddr.toString().c_str(), size);
+#endif
     }
 
     return true;
diff --git a/src/core/gba/gbaRemote.cpp b/src/core/gba/gbaRemote.cpp
index 9ba9923e..76ec669b 100644
--- a/src/core/gba/gbaRemote.cpp
+++ b/src/core/gba/gbaRemote.cpp
@@ -50,6 +50,7 @@
 
 #if __STDC_WANT_SECURE_LIB__
 #define snprintf sprintf_s
+#define sscanf sscanf_s
 #endif
 
 extern int emulating;
@@ -392,7 +393,11 @@ void debuggerDumpLoad(int n, char** args)
             return;
         }
 
+#if __STDC_WANT_SECURE_LIB__
+        fopen_s(&f, file, "rb");
+#else
         f = fopen(file, "rb");
+#endif
         if (f == NULL) {
             {
                 snprintf(monbuf, sizeof(monbuf), "Error opening file.\n");
@@ -442,7 +447,12 @@ void debuggerDumpSave(int n, char** args)
             return;
         }
 
+#if __STDC_WANT_SECURE_LIB__
+        fopen_s(&f, file, "wb");
+#else
         f = fopen(file, "wb");
+#endif
+
         if (f == NULL) {
             {
                 snprintf(monbuf, sizeof(monbuf), "Error opening file.\n");
@@ -935,10 +945,18 @@ void debuggerFindText(int n, char** args)
 
         if (n == 4) {
             sscanf(args[2], "%u", &SearchMaxMatches);
+#if __STDC_WANT_SECURE_LIB__
+            strncpy_s((char*)SearchData, sizeof(SearchData), args[3], 64);
+#else
             strncpy((char*)SearchData, args[3], 64);
+#endif
             SearchLength = (unsigned int)strlen(args[3]);
         } else if (n == 3) {
+#if __STDC_WANT_SECURE_LIB__
+            strncpy_s((char*)SearchData, sizeof(SearchData), args[2], 64);
+#else
             strncpy((char*)SearchData, args[2], 64);
+#endif
             SearchLength = (unsigned int)strlen(args[2]);
         };
 
@@ -971,10 +989,18 @@ void debuggerFindHex(int n, char** args)
         char SearchHex[128];
         if (n == 4) {
             sscanf(args[2], "%u", &SearchMaxMatches);
+#if __STDC_WANT_SECURE_LIB__
+            strncpy_s(SearchHex, sizeof(SearchHex), args[3], 128);
+#else
             strncpy(SearchHex, args[3], 128);
+#endif
             SearchLength = (unsigned int)strlen(args[3]);
         } else if (n == 3) {
+#if __STDC_WANT_SECURE_LIB__
+            strncpy_s(SearchHex, sizeof(SearchHex), args[2], 128);
+#else
             strncpy(SearchHex, args[2], 128);
+#endif
             SearchLength = (unsigned int)strlen(args[2]);
         };
 
@@ -1507,7 +1533,12 @@ void debuggerReadCharTable(int n, char** args)
             }
             return;
         }
+#if __STDC_WANT_SECURE_LIB__
+        FILE* tlb = NULL;
+        fopen_s(&tlb, args[1], "r");
+#else
         FILE* tlb = fopen(args[1], "r");
+#endif
         if (!tlb) {
             {
                 snprintf(monbuf, sizeof(monbuf), "Could not open specified file. Abort.\n");
@@ -1520,8 +1551,11 @@ void debuggerReadCharTable(int n, char** args)
         char* character = (char*)calloc(10, sizeof(char));
         wordSymbol = (char**)calloc(256, sizeof(char*));
         while (fgets(buffer, 30, tlb)) {
-
+#if __STDC_WANT_SECURE_LIB__
+            sscanf_s(buffer, "%02x=%s", &slot, character, 10);
+#else
             sscanf(buffer, "%02x=%s", &slot, character);
+#endif
 
             if (character[0]) {
                 if (strlen(character) == 4) {
@@ -1789,7 +1823,12 @@ void debuggerExecuteCommands(int n, char** args)
         n--;
         args++;
         while (n) {
+#if __STDC_WANT_SECURE_LIB__
+            FILE* toExec = NULL;
+            fopen_s(&toExec, args[0], "r");
+#else
             FILE* toExec = fopen(args[0], "r");
+#endif
             if (toExec) {
                 while (fgets(buffer, 4096, toExec)) {
                     std::string buf(buffer);
@@ -3388,7 +3427,11 @@ void dbgExecute(char* toRun)
 void dbgExecute(std::string& cmd)
 {
     char* dbgCmd = new char[cmd.length() + 1];
+#if __STDC_WANT_SECURE_LIB__
+    strcpy_s(dbgCmd, cmd.length() + 1, cmd.c_str());
+#else
     strcpy(dbgCmd, cmd.c_str());
+#endif
     dbgExecute(dbgCmd);
     delete[] dbgCmd;
 }
@@ -4314,7 +4357,11 @@ void monprintf(std::string line)
 
     if (output.length() <= 1000) {
         char dbgReply[1000];
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(dbgReply, sizeof(dbgReply), output.c_str());
+#else
         strcpy(dbgReply, output.c_str());
+#endif
         remotePutPacket(dbgReply);
     }
 }
diff --git a/src/core/gba/gbaRtc.cpp b/src/core/gba/gbaRtc.cpp
index 56bd17d5..d8c4d876 100644
--- a/src/core/gba/gbaRtc.cpp
+++ b/src/core/gba/gbaRtc.cpp
@@ -111,7 +111,11 @@ void SetGBATime()
 {
     time_t long_time;
     time(&long_time); /* Get time as long integer. */
+#if __STDC_WANT_SECURE_LIB__
+    localtime_s(&gba_time, &long_time); /* Convert to local time. */
+#else
     gba_time = *localtime(&long_time); /* Convert to local time. */
+#endif
 }
 
 void rtcUpdateTime(int ticks)
diff --git a/src/core/gba/internal/gbaBreakpoint.cpp b/src/core/gba/internal/gbaBreakpoint.cpp
index 0dac4ac5..57374a55 100644
--- a/src/core/gba/internal/gbaBreakpoint.cpp
+++ b/src/core/gba/internal/gbaBreakpoint.cpp
@@ -110,6 +110,7 @@ sw, sword, int32_t, int                 --> signed word
 
 #if (defined __WIN32__ || defined _WIN32)
 #define strdup _strdup
+#define sscanf sscanf_s
 #endif
 
 extern bool dexp_eval(char*, uint32_t*);
diff --git a/src/sdl/ConfigManager.cpp b/src/sdl/ConfigManager.cpp
index ba07d44c..74ce0de6 100644
--- a/src/sdl/ConfigManager.cpp
+++ b/src/sdl/ConfigManager.cpp
@@ -18,6 +18,7 @@
 
 #if __STDC_WANT_SECURE_LIB__
 #define snprintf sprintf_s
+#define sscanf sscanf_s
 #endif
 
 #define getcwd _getcwd
@@ -472,7 +473,13 @@ const char* FindConfigFile(const char *name)
 	}
 
 #ifdef _WIN32
+#if __STDC_WANT_SECURE_LIB__
+        char *home = NULL;
+        size_t home_sz = 0;
+        _dupenv_s(&home, &home_sz, "USERPROFILE");
+#else
 	char *home = getenv("USERPROFILE");
+#endif
 	if (home != NULL) {
 		snprintf(path, "%s%c%s", home, kFileSep, name);
 		if (FileExists(path))
@@ -483,12 +490,28 @@ const char* FindConfigFile(const char *name)
 
 	if (!strchr(arg0, '/') &&
 		!strchr(arg0, '\\')) {
+#if __STDC_WANT_SECURE_LIB__
+		char *env_path = NULL;
+                size_t env_path_sz = 0;
+                _dupenv_s(&env_path, &env_path_sz, "PATH");
+#else
 		char *env_path = getenv("PATH");
+#endif
 
 		if (env_path != NULL) {
+#if __STDC_WANT_SECURE_LIB__
+			strncpy_s(buffer, sizeof(buffer), env_path, 4096);
+#else
 			strncpy(buffer, env_path, 4096);
+#endif
 			buffer[4095] = 0;
+#if __STDC_WANT_SECURE_LIB__
+                        char *next_tok1 = NULL;
+                        char *next_tok2 = NULL;
+			char *tok = strtok_s(buffer, PATH_SEP, &next_tok1);
+#else
 			char *tok = strtok(buffer, PATH_SEP);
+#endif
 
 			while (tok) {
 				snprintf(env_path, 4096, "%s%c%s", tok, kFileSep, EXE_NAME);
@@ -499,13 +522,21 @@ const char* FindConfigFile(const char *name)
 						return path2;
 					}
 				}
+#if __STDC_WANT_SECURE_LIB__
+				tok = strtok_s(NULL, PATH_SEP, &next_tok2);
+#else
 				tok = strtok(NULL, PATH_SEP);
+#endif
 			}
 		}
 	}
 	else {
 		// executable is relative to some directory
+#if __STDC_WANT_SECURE_LIB__
+		strcpy_s(buffer, sizeof(buffer), arg0);
+#else
 		strcpy(buffer, arg0);
+#endif
 		char *p = strrchr(buffer, kFileSep);
 		if (p) {
 			*p = 0;
@@ -550,7 +581,11 @@ void SaveConfigFile()
 		FILE *f = utilOpenFile(configFile, "w");
 		if (f == NULL) {
                         char err_msg[4096] = "unknown error";
+#if __STDC_WANT_SECURE_LIB__
+                        strerror_s(err_msg, sizeof(err_msg), errno);
+#else
                         strncpy(err_msg, strerror(errno), 4096);
+#endif
 			fprintf(stderr, "Configuration file '%s' could not be written to: %s\n", configFile, err_msg);
 			return;
 		}
@@ -633,7 +668,11 @@ static char *xstrdup(const char *s)
                 return NULL;
         t = (char *)malloc(strlen(s) + 1);
         if (t) {
+#if __STDC_WANT_SECURE_LIB__
+                strcpy_s(t, strlen(s) + 1, s);
+#else
                 strcpy(t, s);
+#endif
         }
         return t;
 }
@@ -659,7 +698,11 @@ int ReadOpts(int argc, char ** argv)
 		  {
 			  //char* cpy;
 			  //cpy = (char *)malloc(1 + strlen(optarg));
+			  //#if __STDC_WANT_SECURE_LIB__
+			  //strcpy_s(cpy, 1 + strlen(optarg), optarg);
+			  //#else
 			  //strcpy(cpy, optarg);
+			  //#endif
 			  //preparedCheatCodes[preparedCheats++] = cpy;
 			std::string cpy = optarg;
 			preparedCheatCodes[preparedCheats++] = cpy.c_str();
@@ -712,7 +755,11 @@ int ReadOpts(int argc, char ** argv)
 			}
 			else {
 				patchNames[patchNum] = (char *)malloc(1 + strlen(optarg));
+#if __STDC_WANT_SECURE_LIB__
+				strcpy_s(patchNames[patchNum], 1 + strlen(optarg), optarg);
+#else
 				strcpy(patchNames[patchNum], optarg);
+#endif
 				patchNum++;
 			}
 			break;
diff --git a/src/sdl/SDL.cpp b/src/sdl/SDL.cpp
index 20ffd1a6..e3f20057 100644
--- a/src/sdl/SDL.cpp
+++ b/src/sdl/SDL.cpp
@@ -388,9 +388,17 @@ char* sdlGetFilename(const char* name)
     char path[1024];
     const char *_filename = strrchr(name, kFileSep);
     if (_filename)
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(path, sizeof(path), _filename + 1);
+#else
         strcpy(path, _filename + 1);
+#endif
     else
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(path, sizeof(path), name);
+#else
         strcpy(path, name);
+#endif
     return strdup(path);
 }
 
@@ -432,7 +440,12 @@ FILE* sdlFindFile(const char* name)
         fprintf(stdout, "Searching current directory: %s\n", buffer);
     }
 
+#if __STDC_WANT_SECURE_LIB__
+    FILE* f = NULL;
+    fopen_s(&f, name, "r");
+#else
     FILE* f = fopen(name, "r");
+#endif
     if (f != NULL) {
         return f;
     }
@@ -440,55 +453,105 @@ FILE* sdlFindFile(const char* name)
     if (strlen(homeDataDir)) {
         fprintf(stdout, "Searching home directory: %s\n", homeDataDir);
         snprintf(path, sizeof(path), "%s%c%s", homeDataDir, kFileSep, name);
+#if __STDC_WANT_SECURE_LIB__
+        fopen_s(&f, path, "r");
+#else
         f = fopen(path, "r");
+#endif
         if (f != NULL)
             return f;
     }
 
 #ifdef _WIN32
+#if __STDC_WANT_SECURE_LIB__
+    char* profileDir = NULL;
+    size_t profileDirSz = 0;
+    _dupenv_s(&profileDir, &profileDirSz, "USERPROFILE");
+#else
     char* profileDir = getenv("USERPROFILE");
+#endif
     if (profileDir != NULL) {
         fprintf(stdout, "Searching user profile directory: %s\n", profileDir);
         snprintf(path, sizeof(path), "%s%c%s", profileDir, kFileSep, name);
+#if __STDC_WANT_SECURE_LIB__
+        fopen_s(&f, path, "r");
+#else
         f = fopen(path, "r");
+#endif
         if (f != NULL)
             return f;
     }
 
     if (!strchr(home, '/') && !strchr(home, '\\')) {
+#if __STDC_WANT_SECURE_LIB__
+        char* _path = NULL;
+        size_t _pathSz = 0;
+        _dupenv_s(&_path, &_pathSz, "PATH");
+#else
         char* _path = getenv("PATH");
+#endif
 
         if (_path != NULL) {
             fprintf(stdout, "Searching PATH\n");
+#if __STDC_WANT_SECURE_LIB__
+            strcpy_s(buffer, sizeof(buffer), _path);
+#else
             strcpy(buffer, _path);
+#endif
             buffer[sizeof(buffer) - 1] = 0;
+#if __STDC_WANT_SECURE_LIB__
+            char* tok_next1 = NULL;
+            char* tok_next2 = NULL;
+            char* tok = strtok_s(buffer, PATH_SEP, &tok_next1);
+#else
             char* tok = strtok(buffer, PATH_SEP);
+#endif
 
             while (tok) {
                 snprintf(path, sizeof(path), "%s%c%s", tok, kFileSep, EXE_NAME);
+#if __STDC_WANT_SECURE_LIB__
+                fopen_s(&f, path, "r");
+#else
                 f = fopen(path, "r");
+#endif
                 if (f != NULL) {
                     char path2[2048];
                     fclose(f);
                     snprintf(path2, sizeof(path2), "%s%c%s", tok, kFileSep, name);
+#if __STDC_WANT_SECURE_LIB__
+                    fopen_s(&f, path2, "r");
+#else
                     f = fopen(path2, "r");
+#endif
                     if (f != NULL) {
                         fprintf(stdout, "Found at %s\n", path2);
                         return f;
                     }
                 }
+#if __STDC_WANT_SECURE_LIB__
+                tok = strtok_s(NULL, PATH_SEP, &tok_next2);
+#else
                 tok = strtok(NULL, PATH_SEP);
+#endif
             }
         }
     } else {
         // executable is relative to some directory
         fprintf(stdout, "Searching executable directory\n");
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(buffer, sizeof(buffer), home);
+#else
         strcpy(buffer, home);
+#endif
         char* p = strrchr(buffer, kFileSep);
         if (p) {
             *p = 0;
             snprintf(path, sizeof(path), "%s%c%s", buffer, kFileSep, name);
+#if __STDC_WANT_SECURE_LIB__
+            fopen_s(&f, path, "r");
+#else
             f = fopen(path, "r");
+#endif
             if (f != NULL)
                 return f;
         }
@@ -496,13 +559,21 @@ FILE* sdlFindFile(const char* name)
 #else // ! _WIN32
     fprintf(stdout, "Searching data directory: %s\n", PKGDATADIR);
     snprintf(path, sizeof(path), "%s%c%s", PKGDATADIR, kFileSep, name);
+#if __STDC_WANT_SECURE_LIB__
+    fopen_s(&f, path, "r");
+#else
     f = fopen(path, "r");
+#endif
     if (f != NULL)
         return f;
 
     fprintf(stdout, "Searching system config directory: %s\n", SYSCONF_INSTALL_DIR);
     snprintf(path, sizeof(path), "%s%c%s", SYSCONF_INSTALL_DIR, kFileSep, name);
+#if __STDC_WANT_SECURE_LIB__
+    fopen_s(&f, path, "r");
+#else
     f = fopen(path, "r");
+#endif
     if (f != NULL)
         return f;
 #endif // ! _WIN32
@@ -631,7 +702,12 @@ static void sdlApplyPerImagePreferences()
         if (p)
             *p = 0;
 
+#if __STDC_WANT_SECURE_LIB__
+        char* token_next = NULL;
+        char* token = strtok_s(s, " \t\n\r=", &token_next);
+#else
         char* token = strtok(s, " \t\n\r=");
+#endif
 
         if (!token)
             continue;
@@ -655,7 +731,12 @@ static void sdlApplyPerImagePreferences()
             if (p)
                 *p = 0;
 
+#if __STDC_WANT_SECURE_LIB__
+            char* token_next = NULL;
+            char* token = strtok_s(s, " \t\n\r=", &token_next);
+#else
             char* token = strtok(s, " \t\n\r=");
+#endif
             if (!token)
                 continue;
             if (strlen(token) == 0)
@@ -663,7 +744,12 @@ static void sdlApplyPerImagePreferences()
 
             if (token[0] == '[') // starting another image settings
                 break;
+#if __STDC_WANT_SECURE_LIB__
+            char* value_next = NULL;
+            char* value = strtok_s(NULL, "\t\n\r=", &value_next);
+#else
             char* value = strtok(NULL, "\t\n\r=");
+#endif
             if (value == NULL)
                 continue;
 
@@ -774,13 +860,25 @@ void sdlWriteBackupStateExchange(int from, int to, int backup)
 
     dmp = sdlStateName(from);
     stateNameOrig = (char*)realloc(stateNameOrig, strlen(dmp) + 1);
+#if __STDC_WANT_SECURE_LIB__
+    strcpy_s(stateNameOrig, strlen(dmp) + 1, dmp);
+#else
     strcpy(stateNameOrig, dmp);
+#endif
     dmp = sdlStateName(to);
     stateNameDest = (char*)realloc(stateNameDest, strlen(dmp) + 1);
+#if __STDC_WANT_SECURE_LIB__
+    strcpy_s(stateNameDest, strlen(dmp) + 1, dmp);
+#else
     strcpy(stateNameDest, dmp);
+#endif
     dmp = sdlStateName(backup);
     stateNameBack = (char*)realloc(stateNameBack, strlen(dmp) + 1);
+#if __STDC_WANT_SECURE_LIB__
+    strcpy_s(stateNameBack, strlen(dmp) + 1, dmp);
+#else
     strcpy(stateNameBack, dmp);
+#endif
 
     /* on POSIX, rename would not do anything anyway for identical names, but let's check it ourselves anyway */
     if (to != backup) {
@@ -2078,7 +2176,7 @@ int main(int argc, char** argv)
     if (optind < argc) {
         char* szFile = argv[optind];
 
-        utilStripDoubleExtension(szFile, filename);
+        utilStripDoubleExtension(szFile, filename, sizeof(filename));
         char* p = strrchr(filename, '.');
 
         if (p)
@@ -2173,7 +2271,11 @@ int main(int argc, char** argv)
     } else {
         soundInit();
         cartridgeType = 0;
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(filename, sizeof(filename), "gnu_stub");
+#else
         strcpy(filename, "gnu_stub");
+#endif
         g_rom = (uint8_t*)malloc(0x2000000);
         g_workRAM = (uint8_t*)calloc(1, 0x40000);
         g_bios = (uint8_t*)calloc(1, 0x4000);
@@ -2678,7 +2780,11 @@ void systemConsoleMessage(const char* msg)
     struct tm now_time_broken;
 
     now_time = time(NULL);
+#if __STDC_WANT_SECURE_LIB__
+    localtime_s(&now_time_broken, &now_time);
+#else
     now_time_broken = *(localtime(&now_time));
+#endif
     fprintf(
         stdout,
         "%02d:%02d:%02d %02d.%02d.%4d: %s\n",
@@ -2697,10 +2803,18 @@ void systemScreenMessage(const char* msg)
     screenMessage = true;
     screenMessageTime = systemGetClock();
     if (strlen(msg) > 20) {
+#if __STDC_WANT_SECURE_LIB__
+        strncpy_s(screenMessageBuffer, sizeof(screenMessageBuffer), msg, 20);
+#else
         strncpy(screenMessageBuffer, msg, 20);
+#endif
         screenMessageBuffer[20] = 0;
     } else
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(screenMessageBuffer, sizeof(screenMessageBuffer), msg);
+#else
         strcpy(screenMessageBuffer, msg);
+#endif
 
     systemConsoleMessage(msg);
 }
@@ -2799,7 +2913,11 @@ void log(const char* defaultMsg, ...)
     static FILE* out = NULL;
 
     if (out == NULL) {
+#if __STDC_WANT_SECURE_LIB__
+        fopen_s(&out, "trace.log", "w");
+#else
         out = fopen("trace.log", "w");
+#endif
     }
 
     va_list valist;
diff --git a/src/sdl/dictionary.c b/src/sdl/dictionary.c
index d6841cb0..77807b1b 100644
--- a/src/sdl/dictionary.c
+++ b/src/sdl/dictionary.c
@@ -68,7 +68,11 @@ static char *xstrdup(const char *s)
                 return NULL;
         t = (char *)malloc(strlen(s) + 1);
         if (t) {
+#if __STDC_WANT_SECURE_LIB__
+                strcpy_s(t, strlen(s) + 1, s);
+#else
                 strcpy(t, s);
+#endif
         }
         return t;
 }
diff --git a/src/sdl/iniparser.c b/src/sdl/iniparser.c
index 0de0b259..b2e0e899 100644
--- a/src/sdl/iniparser.c
+++ b/src/sdl/iniparser.c
@@ -13,6 +13,7 @@
 
 #if __STDC_WANT_SECURE_LIB__
 #define snprintf sprintf_s
+#define sscanf sscanf_s
 #endif
 
 /*---------------------------- Defines -------------------------------------*/
@@ -89,7 +90,11 @@ static char *strstrip(const char *s)
         while (isspace((int)*s) && *s)
                 s++;
         memset(l, 0, ASCIILINESZ + 1);
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(l, sizeof(l), s);
+#else
         strcpy(l, s);
+#endif
         last = l + strlen(l);
         while (last > l) {
                 if (!isspace((int)*(last - 1)))
@@ -577,7 +582,11 @@ static line_status iniparser_line(const char *input_line, char *section, char *k
         char line[ASCIILINESZ + 1];
         int len;
 
+#if __STDC_WANT_SECURE_LIB__
+        strcpy_s(line, sizeof(line), strstrip(input_line));
+#else
         strcpy(line, strstrip(input_line));
+#endif
         len = (int)strlen(line);
 
         sta = LINE_UNPROCESSED;
@@ -589,6 +598,19 @@ static line_status iniparser_line(const char *input_line, char *section, char *k
                 sta = LINE_COMMENT;
         } else if (line[0] == '[' && line[len - 1] == ']') {
                 /* Section name */
+#if __STDC_WANT_SECURE_LIB__
+                sscanf_s(line, "[%[^]]", section, (unsigned)_countof(section));
+                strcpy_s(section, ASCIILINESZ, strstrip(section));
+                strcpy_s(section, ASCIILINESZ, strlwc(section));
+                sta = LINE_SECTION;
+        } else if (sscanf_s(line, "%[^=] = \"%[^\"]\"", key, (unsigned)_countof(key), value, (unsigned)_countof(value)) == 2 ||
+                   sscanf_s(line, "%[^=] = '%[^\']'", key, (unsigned)_countof(key), value, (unsigned)_countof(value)) == 2 ||
+                   sscanf_s(line, "%[^=] = %[^;#]", key, (unsigned)_countof(key), value, (unsigned)_countof(value)) == 2) {
+               /* Usual key=value, with or without comments */
+                strcpy_s(key, ASCIILINESZ, strstrip(key));
+                strcpy_s(key, ASCIILINESZ, strlwc(key));
+                strcpy_s(value, ASCIILINESZ, strstrip(value));
+#else
                 sscanf(line, "[%[^]]", section);
                 strcpy(section, strstrip(section));
                 strcpy(section, strlwc(section));
@@ -596,10 +618,11 @@ static line_status iniparser_line(const char *input_line, char *section, char *k
         } else if (sscanf(line, "%[^=] = \"%[^\"]\"", key, value) == 2 ||
                    sscanf(line, "%[^=] = '%[^\']'", key, value) == 2 ||
                    sscanf(line, "%[^=] = %[^;#]", key, value) == 2) {
-                /* Usual key=value, with or without comments */
+               /* Usual key=value, with or without comments */
                 strcpy(key, strstrip(key));
                 strcpy(key, strlwc(key));
                 strcpy(value, strstrip(value));
+ #endif
                 /*
                  * sscanf cannot handle '' or "" as empty values
                  * this is done here
@@ -608,16 +631,26 @@ static line_status iniparser_line(const char *input_line, char *section, char *k
                         value[0] = 0;
                 }
                 sta = LINE_VALUE;
+#if __STDC_WANT_SECURE_LIB__
+        } else if (sscanf_s(line, "%[^=] = %[;#]", key, (unsigned)_countof(key), value, (unsigned)_countof(value)) == 2 ||
+                   sscanf_s(line, "%[^=] %[=]", key, (unsigned)_countof(key), value, (unsigned)_countof(value)) == 2) {
+#else
         } else if (sscanf(line, "%[^=] = %[;#]", key, value) == 2 ||
                    sscanf(line, "%[^=] %[=]", key, value) == 2) {
+#endif
                 /*
                  * Special cases:
                  * key=
                  * key=;
                  * key=#
                  */
+#if __STDC_WANT_SECURE_LIB__
+                strcpy_s(key, ASCIILINESZ, strstrip(key));
+                strcpy_s(key, ASCIILINESZ, strlwc(key));
+#else
                 strcpy(key, strstrip(key));
                 strcpy(key, strlwc(key));
+#endif
                 value[0] = 0;
                 sta = LINE_VALUE;
         } else {
@@ -658,7 +691,12 @@ dictionary *iniparser_load(const char *ininame)
 
         dictionary *dict;
 
+#if __STDC_WANT_SECURE_LIB__
+        fopen_s(&in, ininame, "r");
+        if (in == NULL) {
+#else
         if ((in = fopen(ininame, "r")) == NULL) {
+#endif
                 fprintf(stderr, "iniparser: cannot open %s\n", ininame);
                 return NULL;
         }
diff --git a/src/wx/bin2c.c b/src/wx/bin2c.c
index 6c6e40f7..73dc2532 100644
--- a/src/wx/bin2c.c
+++ b/src/wx/bin2c.c
@@ -48,9 +48,15 @@ const char* msg_prefix = "bin2c: ";
 void format_perror(const char* fmt, va_list args) {
     static char error_str[MSG_SIZE];
     static char fmt_str[MSG_SIZE];
+#if __STDC_WANT_SECURE_LIB__
+    strcpy_s(fmt_str, sizeof(fmt_str), msg_prefix);
+    strncat_s(fmt_str, sizeof(fmt_str), fmt, MSG_SIZE - strlen(msg_prefix));
+    vsprintf_s(error_str, MSG_SIZE, fmt_str, args);
+#else
     strcpy(fmt_str, msg_prefix);
     strncat(fmt_str, fmt, MSG_SIZE - strlen(msg_prefix));
     vsnprintf(error_str, MSG_SIZE, fmt_str, args);
+#endif
     perror(error_str);
 }
 
@@ -80,7 +86,11 @@ char* file_name_to_identifier(const char* file_name_cstr) {
     size_t   file_name_len   = 0;
     int between_tokens       = 0;
 
+#if __STDC_WANT_SECURE_LIB__
+    mbstowcs_s(&file_name_len, file_name, WBUF_SIZE, file_name_cstr, BUF_SIZE - 1);
+#else
     file_name_len = mbstowcs(file_name, file_name_cstr, BUF_SIZE - 1);
+#endif
     if (file_name_len == (size_t)(-1)) {
         die("cannot convert '%s' to locale representation", file_name_cstr);
     }
@@ -96,7 +106,12 @@ char* file_name_to_identifier(const char* file_name_cstr) {
             between_tokens = 0;
         }
         else if (!between_tokens) {
+#if __STDC_WANT_SECURE_LIB__
+            size_t identifier_ptr_sz = 0;
+            mbstowcs_s(&identifier_ptr_sz, identifier_ptr, WBUF_SIZE, "_", 1);
+#else
             mbstowcs(identifier_ptr, "_", 1);
+#endif
             identifier_ptr++;
             between_tokens  = 1;
         }
@@ -109,7 +124,13 @@ char* file_name_to_identifier(const char* file_name_cstr) {
 
     *identifier_ptr = 0;
 
+#if __STDC_WANT_SECURE_LIB__
+    size_t identifier_cstr_sz = 0;
+    wcstombs_s(&identifier_cstr_sz, identifier_cstr, BUF_SIZE, identifier, WBUF_SIZE - 1);
+    if (identifier_cstr_sz == (size_t)(-1))
+#else
     if (wcstombs(identifier_cstr, identifier, WBUF_SIZE - 1) == (size_t)(-1))
+#endif
         die("failed to convert wide character string to bytes");
 
     free(file_name);
@@ -151,10 +172,19 @@ void die_usage(const char* fmt, ...) {
     static char fmt_str[MSG_SIZE];
     va_list args;
     va_start(args, fmt);
+#if __STDC_WANT_SECURE_LIB__
+    strcpy_s(fmt_str, sizeof(fmt_str), msg_prefix);
+#else
     strcpy(fmt_str, msg_prefix);
+#endif
     // Need to reserve 1 byte for the newline.
+#if __STDC_WANT_SECURE_LIB__
+    strncat_s(fmt_str, sizeof(fmt_str), fmt, MSG_SIZE - strlen(msg_prefix) - 1);
+    strcat_s(fmt_str, sizeof(fmt_str), "\n");
+#else
     strncat(fmt_str, fmt, MSG_SIZE - strlen(msg_prefix) - 1);
     strcat(fmt_str, "\n");
+#endif
     vfprintf(stderr, fmt_str, args);
     va_end(args);
     usage(1);
@@ -200,7 +230,11 @@ int main(int argc, const char** argv) {
     if (!in_file_name || !strcmp(in_file_name, "-")) {
         in_file = stdin;
     } else {
+#if __STDC_WANT_SECURE_LIB__
+        fopen_s(&in_file, in_file_name, "rb");
+#else
         in_file = fopen(in_file_name, "rb");
+#endif
         if (!in_file) {
             die("can't open input file '%s'", in_file_name);
         }
@@ -209,7 +243,11 @@ int main(int argc, const char** argv) {
     if (!out_file_name || !strcmp(out_file_name, "-")) {
         out_file = stdout;
     } else {
+#if __STDC_WANT_SECURE_LIB__
+        fopen_s(&out_file, out_file_name, "w");
+#else
         out_file = fopen(out_file_name, "w");
+#endif
         if (!out_file) {
             die("can't open output file '%s'", out_file_name);
         }
diff --git a/src/wx/guiinit.cpp b/src/wx/guiinit.cpp
index ee60d8f9..25e5b7b1 100644
--- a/src/wx/guiinit.cpp
+++ b/src/wx/guiinit.cpp
@@ -67,6 +67,10 @@ const
 #undef wxvbam
 #endif
 
+#if __STDC_WANT_SECURE_LIB__
+#define sscanf sscanf_s
+#endif
+
 #define GetXRCDialog(n) \
     wxStaticCast(wxGetApp().frame->FindWindowByName(n), wxDialog)
 
@@ -650,7 +654,11 @@ public:
         } else if (ce_desc != odesc) {
             *dirty = true;
             char* p = isgb ? gbCheatList[id].cheatDesc : cheatsList[id].desc;
+#if __STDC_WANT_SECURE_LIB__
+            strncpy_s(p, sizeof(cheatsList[0].desc), ce_desc.utf8_str(), sizeof(cheatsList[0].desc));
+#else
             strncpy(p, ce_desc.utf8_str(), sizeof(cheatsList[0].desc));
+#endif
             p[sizeof(cheatsList[0].desc) - 1] = 0;
             item1.SetId(id);
             item1.SetText(wxString(p, wxConvUTF8));
diff --git a/src/wx/wxvbam.cpp b/src/wx/wxvbam.cpp
index 2223f020..0307d1d8 100644
--- a/src/wx/wxvbam.cpp
+++ b/src/wx/wxvbam.cpp
@@ -107,8 +107,15 @@ int __stdcall WinMain(HINSTANCE hInstance,
     // https://github.com/dolphin-emu/dolphin/blob/6cf99195c645f54d54c72322ad0312a0e56bc985/Source/Core/DolphinQt/Main.cpp#L112
     HANDLE stdout_handle = GetStdHandle(STD_OUTPUT_HANDLE);
     if (console_attached && stdout_handle) {
+#if __STDC_WANT_SECURE_LIB__
+        FILE *ostream;
+        FILE *estream;
+        freopen_s(&ostream, "CONOUT$", "w", stdout);
+        freopen_s(&estream, "CONOUT$", "w", stderr);
+#else
         freopen("CONOUT$", "w", stdout);
         freopen("CONOUT$", "w", stderr);
+#endif
     }
 
     // Set up logging.
diff --git a/third_party/sfml/src/SFML/System/Utils.cpp b/third_party/sfml/src/SFML/System/Utils.cpp
index a4aff623..00b8f6e9 100644
--- a/third_party/sfml/src/SFML/System/Utils.cpp
+++ b/third_party/sfml/src/SFML/System/Utils.cpp
@@ -56,7 +56,13 @@ std::FILE* openFile(const ghc::filesystem::path& filename, std::string mode)
 {
 #ifdef SFML_SYSTEM_WINDOWS
     const std::wstring wmode(mode.begin(), mode.end());
+#if __STDC_WANT_SECURE_LIB__
+    std::FILE* ret = NULL;
+    _wfopen_s(&ret, filename.c_str(), wmode.data());
+    return ret;
+#else
     return _wfopen(filename.c_str(), wmode.data());
+#endif
 #else
     return std::fopen(filename.c_str(), mode.data());
 #endif