-FGAPI void FGAPIENTRY glutBitmapString( void* font, const char *string );
-FGAPI void FGAPIENTRY glutStrokeString( void* font, const char *string );
+FGAPI void FGAPIENTRY glutBitmapString( void* font, const unsigned char *string );
+FGAPI void FGAPIENTRY glutStrokeString( void* font, const unsigned char *string );