diff --git a/pcsx2/Common.h b/pcsx2/Common.h
index 762df62252..af2cd88530 100644
--- a/pcsx2/Common.h
+++ b/pcsx2/Common.h
@@ -235,7 +235,7 @@ extern TESTRUNARGS g_TestRun;
 
 int cdCaseopen;
 
-extern void __Log(char *fmt, ...);
+extern void __Log(const char *fmt, ...);
 extern u16 logProtocol;
 extern u8  logSource;
 #define PCSX2_VERSION "0.9.5"
diff --git a/pcsx2/DebugTools/Debug.h b/pcsx2/DebugTools/Debug.h
index 1b149bcedb..2081c26673 100644
--- a/pcsx2/DebugTools/Debug.h
+++ b/pcsx2/DebugTools/Debug.h
@@ -56,7 +56,7 @@ extern u32 varLog;
 extern u16 logProtocol;
 extern u8  logSource;
 
-void __Log(char *fmt, ...);
+void __Log(const char *fmt, ...);
 
 //memcars has the same number as PAD_LOG
 #define MEMCARDS_LOG if (varLog & 0x02000000) {logProtocol=7; logSource='I';} if (varLog & 0x02000000) __Log
diff --git a/pcsx2/Linux/GtkGui.c b/pcsx2/Linux/GtkGui.c
index 3e209f3a68..ce16f11cbc 100644
--- a/pcsx2/Linux/GtkGui.c
+++ b/pcsx2/Linux/GtkGui.c
@@ -1518,7 +1518,7 @@ void OnMsg_Ok() {
 	gtk_main_quit();
 }
 
-void SysMessage(char *fmt, ...) {
+void SysMessage(const char *fmt, ...) {
 	GtkWidget *Ok,*Txt;
 	GtkWidget *Box,*Box1;
 	va_list list;
diff --git a/pcsx2/Linux/LnxMain.c b/pcsx2/Linux/LnxMain.c
index 02522a9f0d..13be9d304a 100644
--- a/pcsx2/Linux/LnxMain.c
+++ b/pcsx2/Linux/LnxMain.c
@@ -371,7 +371,7 @@ void SysClose() {
     }
 }
 
-void SysPrintf(char *fmt, ...) {
+void SysPrintf(const char *fmt, ...) {
 	va_list list;
 	char msg[512];
 	char* ptr, *src;
diff --git a/pcsx2/Misc.c b/pcsx2/Misc.c
index 32f738325b..117084e86a 100644
--- a/pcsx2/Misc.c
+++ b/pcsx2/Misc.c
@@ -450,7 +450,7 @@ int connected=0;
 
 #define SYNC_LOGGING
 
-void __Log(char *fmt, ...) {
+void __Log(const char *fmt, ...) {
 #ifdef EMU_LOG 
 	va_list list;
 	static char tmp[2024];	//hm, should be enough
diff --git a/pcsx2/Misc.h b/pcsx2/Misc.h
index 012a355b93..53425ad126 100644
--- a/pcsx2/Misc.h
+++ b/pcsx2/Misc.h
@@ -258,7 +258,7 @@ void memxor_mmx(void* dst, const void* src1, int cmpsize);
 #pragma pack()
 #endif
 
-void __Log(char *fmt, ...);
+void __Log(const char *fmt, ...);
 void injectIRX(char *filename);
 
 #if !defined(_MSC_VER) && !defined(HAVE_ALIGNED_MALLOC)
diff --git a/pcsx2/System.h b/pcsx2/System.h
index 4ca37ea18a..cc30facf59 100644
--- a/pcsx2/System.h
+++ b/pcsx2/System.h
@@ -21,8 +21,8 @@
 
 int  SysInit();							// Init mem and plugins
 void SysReset();						// Resets mem
-void SysPrintf(char *fmt, ...);			// Printf used by bios syscalls
-void SysMessage(char *fmt, ...);		// Message used to print msg to users
+void SysPrintf(const char *fmt, ...);			// Printf used by bios syscalls
+void SysMessage(const char *fmt, ...);		// Message used to print msg to users
 void SysUpdate();						// Called on VBlank (to update i.e. pads)
 void SysRunGui();						// Returns to the Gui
 void SysClose();						// Close mem and plugins
diff --git a/pcsx2/configure.ac b/pcsx2/configure.ac
index e80ac00e12..3edb122b8b 100644
--- a/pcsx2/configure.ac
+++ b/pcsx2/configure.ac
@@ -23,16 +23,16 @@ AC_ARG_ENABLE(debug, AC_HELP_STRING([--enable-debug], [debug build]),
 if test "x$debug" == xyes
 then
  AC_DEFINE(_DEBUG,1,[_DEBUG])
- CFLAGS+=" -g "
- CPPFLAGS+=" -g "
- CXXFLAGS+=" -g "
- CCASFLAGS+=" -D_DEBUG -g "
+ CFLAGS+=" -g   -Wall -Wextra"
+ CPPFLAGS+=" -g  -Wall -Wextra "
+ CXXFLAGS+=" -g   -Wall -Wextra"
+ CCASFLAGS+=" -D_DEBUG -g   -Wall -Wextra"
  MYOBJDIR="Debug"
 else
  AC_DEFINE(NDEBUG,1,[NDEBUG])
- CFLAGS+=" -O3 -fomit-frame-pointer "
- CPPFLAGS+=" -O3 -fomit-frame-pointer "
- CXXFLAGS+=" -O3 -fomit-frame-pointer "
+ CFLAGS+=" -O3 -fomit-frame-pointer   -Wall -Wextra"
+ CPPFLAGS+=" -O3 -fomit-frame-pointer   -Wall -Wextra"
+ CXXFLAGS+=" -O3 -fomit-frame-pointer   -Wall -Wextra"
  MYOBJDIR="Release"
 fi
 AC_MSG_RESULT($debug)
diff --git a/pcsx2/windows/WinMain.c b/pcsx2/windows/WinMain.c
index c65d2830bb..d62558d76b 100644
--- a/pcsx2/windows/WinMain.c
+++ b/pcsx2/windows/WinMain.c
@@ -1622,7 +1622,7 @@ int concolors[] = {
 	FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE
 };
 
-void SysPrintf(char *fmt, ...) {
+void SysPrintf(const char *fmt, ...) {
 	va_list list;
 	char msg[512];
 	char *ptr;
@@ -1680,7 +1680,7 @@ void SysPrintf(char *fmt, ...) {
 	WriteConsole(gApp.hConsole, ptr, (DWORD)strlen(ptr), &tmp, 0);
 }
 
-void SysMessage(char *fmt, ...) {
+void SysMessage(const char *fmt, ...) {
 	va_list list;
 	char tmp[512];
 
diff --git a/pcsx2/x86/iR3000A.h b/pcsx2/x86/iR3000A.h
index da3c5f5ebb..3a2c1472bc 100644
--- a/pcsx2/x86/iR3000A.h
+++ b/pcsx2/x86/iR3000A.h
@@ -18,7 +18,7 @@
 #ifndef _R3000A_SUPERREC_
 #define _R3000A_SUPERREC_
 
-extern void __Log(char *fmt, ...);
+extern void __Log(const char *fmt, ...);
 
 // to be consistent with EE
 #define PSX_HI XMMGPR_HI