diff --git a/plugins/CDVDiso/src/CMakeLists.txt b/plugins/CDVDiso/src/CMakeLists.txt
index 25a841ec25..1fb3fe162e 100644
--- a/plugins/CDVDiso/src/CMakeLists.txt
+++ b/plugins/CDVDiso/src/CMakeLists.txt
@@ -12,7 +12,6 @@ set(Output CDVDiso)
 set(CommonFlags
     -fvisibility=hidden
     -Wall
-    -fpermissive
     )
 
 set(OptimizationFlags
diff --git a/plugins/CDVDiso/src/Linux/Config.cpp b/plugins/CDVDiso/src/Linux/Config.cpp
index 1630943796..92da1ce65f 100644
--- a/plugins/CDVDiso/src/Linux/Config.cpp
+++ b/plugins/CDVDiso/src/Linux/Config.cpp
@@ -91,7 +91,7 @@ void SysMessage(char *fmt, ...)
 
 void OnFile_Ok()
 {
-	gchar *File;
+	const gchar *File;
 
 	gtk_widget_hide(FileSel);
 	File = gtk_file_selection_get_filename(GTK_FILE_SELECTION(FileSel));
@@ -183,7 +183,7 @@ void SysMessageLoc(char *fmt, ...)
 
 void OnOk (GtkButton *button,  gpointer user_data)
 {
-	char *tmp;
+	const char *tmp;
 
 	stop = true;
 	tmp = gtk_entry_get_text(GTK_ENTRY(Edit));
@@ -210,7 +210,7 @@ void OnCancel(GtkButton *button,  gpointer user_data)
 
 void OnFileSel_Ok()
 {
-	gchar *File;
+	const gchar *File;
 
 	File = gtk_file_selection_get_filename(GTK_FILE_SELECTION(FileSel));
 	gtk_entry_set_text(GTK_ENTRY(Edit), File);
@@ -278,7 +278,6 @@ EXPORT_C_(void) CDVDconfigure()
 	gtk_widget_show_all(ConfDlg);
 	gtk_main();
 
-	return 0;
 }
 
 void OnAboutOk(GtkMenuItem * menuitem, gpointer userdata)
diff --git a/plugins/CDVDiso/src/Linux/Linux.cpp b/plugins/CDVDiso/src/Linux/Linux.cpp
index d94105565e..0f9926dde1 100644
--- a/plugins/CDVDiso/src/Linux/Linux.cpp
+++ b/plugins/CDVDiso/src/Linux/Linux.cpp
@@ -45,7 +45,7 @@ void OnStop(GtkButton *button,  gpointer user_data)
 
 void UpdZmode()
 {
-	char *tmp;
+	const char *tmp;
 
 	tmp = gtk_entry_get_text(GTK_ENTRY(GTK_COMBO(Method)->entry));
 	if (!strcmp(tmp, methods[0])) Zmode = 1;
@@ -60,7 +60,7 @@ void OnCompress(GtkButton *button,  gpointer user_data)
 	u32 lsn;
 	u8 cdbuff[10*2352];
 	char Zfile[256];
-	char *tmp;
+	const char *tmp;
 	int ret;
 	isoFile *src;
 	isoFile *dst;
@@ -334,7 +334,7 @@ long CDR_getTD(unsigned char track, unsigned char *buffer)
 //  byte 0 - minute
 //  byte 1 - second
 //  byte 2 - frame
-char *CDR_readTrack(unsigned char *time)
+unsigned char *CDR_readTrack(unsigned char *time)
 {
 	cr.msf.cdmsf_min0 = time[0];
 	cr.msf.cdmsf_sec0 = time[1];
@@ -356,7 +356,7 @@ void OnCreate(GtkButton *button,  gpointer user_data)
 	unsigned char *buffer;
 	unsigned char bufferz[2352];
 	unsigned char start[4], end[4];
-	char *tmp;
+	const char *tmp;
 #ifdef VERBOSE
 	unsigned long count = 0;
 	int i = 0;
@@ -495,7 +495,7 @@ void OnCreateZ(GtkButton *button,  gpointer user_data)
 	unsigned char bufferz[2352];
 	unsigned char start[4], end[4];
 	char table[256];
-	char *tmp;
+	const char *tmp;
 	int b, blocks;
 #ifdef VERBOSE
 	unsigned long count = 0;
@@ -618,7 +618,7 @@ void OnCreateZ(GtkButton *button,  gpointer user_data)
 		if (Zmode == 1)
 			compress(Zbuf, &size, cdbuffer, CD_FRAMESIZE_RAW);
 		else
-			BZ2_bzBuffToBuffCompress(Zbuf, (unsigned int*)&size, cdbuffer, CD_FRAMESIZE_RAW * 10, 1, 0, 30);
+			BZ2_bzBuffToBuffCompress((char*)Zbuf, (unsigned int*)&size, (char*)cdbuffer, CD_FRAMESIZE_RAW * 10, 1, 0, 30);
 
 		fwrite(&c, 1, 4, t);
 		if (Zmode == 1) fwrite(&size, 1, 2, t);
diff --git a/plugins/CDVDiso/src/libiso.cpp b/plugins/CDVDiso/src/libiso.cpp
index 97591936f5..b32d5602a8 100644
--- a/plugins/CDVDiso/src/libiso.cpp
+++ b/plugins/CDVDiso/src/libiso.cpp
@@ -166,7 +166,7 @@ int _readfile(void *handle, void *dst, int size)
 	return ret;
 }
 
-int _writefile(void *handle, void *src, int size)
+int _writefile(void *handle, const void *src, int size)
 {
 	DWORD ret;
 
@@ -198,11 +198,12 @@ void *_openfile(const char *filename, int flags)
 
 u64 _tellfile(void *handle)
 {
-	s64 cursize = ftell(handle);
+	FILE* fp = (FILE*)handle;
+	s64 cursize = ftell(fp);
 	if (cursize == -1)
 	{
 		// try 64bit
-		cursize = ftello64(handle);
+		cursize = ftello64(fp);
 		if (cursize < -1)
 		{
 			// zero top 32 bits
@@ -214,7 +215,7 @@ u64 _tellfile(void *handle)
 
 int _seekfile(void *handle, u64 offset, int whence)
 {
-	int seekerr = fseeko64(handle, offset, whence);
+	int seekerr = fseeko64((FILE*)handle, offset, whence);
 
 	if (seekerr == -1) printf("failed to seek\n");
 
@@ -223,17 +224,17 @@ int _seekfile(void *handle, u64 offset, int whence)
 
 int _readfile(void *handle, void *dst, int size)
 {
-	return fread(dst, 1, size, handle);
+	return fread(dst, 1, size, (FILE*)handle);
 }
 
-int _writefile(void *handle, void *src, int size)
+int _writefile(void *handle, const void *src, int size)
 {
-	return fwrite(src, 1, size, handle);
+	return fwrite(src, 1, size, (FILE*)handle);
 }
 
 void _closefile(void *handle)
 {
-	fclose(handle);
+	fclose((FILE*)handle);
 }
 
 #endif
diff --git a/plugins/CDVDiso/src/libiso.h b/plugins/CDVDiso/src/libiso.h
index 48249837ba..9b19f878c1 100644
--- a/plugins/CDVDiso/src/libiso.h
+++ b/plugins/CDVDiso/src/libiso.h
@@ -61,7 +61,7 @@ void *_openfile(const char *filename, int flags);
 u64 _tellfile(void *handle);
 int _seekfile(void *handle, u64 offset, int whence);
 int _readfile(void *handle, void *dst, int size);
-int _writefile(void *handle, void *src, int size);
+int _writefile(void *handle, const void *src, int size);
 void _closefile(void *handle);
 
 #endif /* __LIBISO_H__ */