diff --git a/desmume/src/NDSSystem.c b/desmume/src/NDSSystem.c
index 4ecfe8a8b..5ec43dc05 100644
--- a/desmume/src/NDSSystem.c
+++ b/desmume/src/NDSSystem.c
@@ -197,6 +197,7 @@ int NDS_LoadROM(const char *filename, int bmtype, u32 bmsize)
       type = ROM_DSGBA;
 
    file = reader->Init(filename);
+	if (!file) return -1 ;
    size = reader->Size(file);
 
    if(type == ROM_DSGBA)
@@ -273,6 +274,8 @@ void NDS_Reset(void)
    u32 dst;
    NDS_header * header = NDS_getROMHeader();
 
+	if (!header) return ;
+
    execute = FALSE;
 
    MMU_clearMem();
diff --git a/desmume/src/ROMReader.c b/desmume/src/ROMReader.c
index 74756d17f..15ff3744e 100644
--- a/desmume/src/ROMReader.c
+++ b/desmume/src/ROMReader.c
@@ -4,6 +4,7 @@
 
 ROMReader_struct * ROMReaderInit(const char ** filename)
 {
+#ifdef HAVE_LIBZ
 	if(!strcasecmp(".gz", *filename + (strlen(*filename) - 3)))
 	{
 		*filename -= 3;
@@ -13,6 +14,9 @@ ROMReader_struct * ROMReaderInit(const char ** filename)
 	{
 		return &STDROMReader;
 	}
+#else
+	return &STDROMReader;
+#endif
 }
 
 void * STDROMReaderInit(const char * filename);
@@ -39,6 +43,7 @@ void * STDROMReaderInit(const char * filename)
 
 void STDROMReaderDeInit(void * file)
 {
+	if (!file) return ;
 	fclose(file);
 }
 
@@ -46,6 +51,8 @@ u32 STDROMReaderSize(void * file)
 {
 	u32 size;
 
+	if (!file) return 0 ;
+
 	fseek(file, 0, SEEK_END);
 	size = ftell(file);
 	fseek(file, 0, SEEK_SET);
@@ -55,11 +62,13 @@ u32 STDROMReaderSize(void * file)
 
 int STDROMReaderSeek(void * file, int offset, int whence)
 {
+	if (!file) return 0 ;
 	return fseek(file, offset, whence);
 }
 
 int STDROMReaderRead(void * file, void * buffer, u32 size)
 {
+	if (!file) return 0 ;
 	return fread(buffer, 1, size, file);
 }