diff --git a/src/dispextern.h b/src/dispextern.h
index 0615b16d712..4bf9f39cd08 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -123,7 +123,9 @@ typedef HDC Emacs_Pix_Context;
 
 #ifdef HAVE_NS
 #include "nsgui.h"
-#define FACE_COLOR_TO_PIXEL(face_color, frame) ns_color_index_to_rgba(face_color, frame)
+#define FACE_COLOR_TO_PIXEL(face_color, frame) (FRAME_NS_P (frame) \
+                                                ? ns_color_index_to_rgba (face_color, frame) \
+                                                : face_color)
 /* Following typedef needed to accommodate the MSDOS port, believe it or not.  */
 typedef struct ns_display_info Display_Info;
 typedef Emacs_Pixmap Emacs_Pix_Container;