diff --git a/src/dispextern.h b/src/dispextern.h
index 579665c2ff8..776d14080e5 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -74,10 +74,13 @@ typedef HDC XImagePtr_or_DC;
 
 #ifdef HAVE_NS
 #include "nsgui.h"
+#define FACE_COLOR_TO_PIXEL(face_color, frame) ns_color_index_to_rgba(face_color, frame)
 /* Following typedef needed to accommodate the MSDOS port, believe it or not.  */
 typedef struct ns_display_info Display_Info;
 typedef Pixmap XImagePtr;
 typedef XImagePtr XImagePtr_or_DC;
+#else
+#define FACE_COLOR_TO_PIXEL(face_color, frame) face_color
 #endif
 
 #ifdef HAVE_WINDOW_SYSTEM
diff --git a/src/nsgui.h b/src/nsgui.h
index 4e7d7d35daa..f858fa7a14a 100644
--- a/src/nsgui.h
+++ b/src/nsgui.h
@@ -73,6 +73,8 @@ typedef unichar XChar2b;
 #define XCHAR2B_BYTE2(chp) \
   (*(chp) & 0x00ff)
 
+/* Used in xdisp.c when comparing faces and frame colors.  */
+extern unsigned long ns_color_index_to_rgba(int idx, struct frame *f);
 
 /* XXX: xfaces requires these structures, but the question is are we
         forced to use them?  */
diff --git a/src/nsterm.m b/src/nsterm.m
index 07978c0d3b8..6ba867d27c0 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -2332,6 +2332,22 @@ so some key presses (TAB) are swallowed by the system.  */
   return 1;
 }
 
+/* Convert an index into the color table into an RGBA value.  Used in
+   xdisp.c:extend_face_to_end_of_line when comparing faces and frame
+   color values.  */
+
+unsigned long
+ns_color_index_to_rgba(int idx, struct frame *f)
+{
+  NSColor *col;
+  col = ns_lookup_indexed_color (idx, f);
+
+  EmacsCGFloat r, g, b, a;
+  [col getRed: &r green: &g blue: &b alpha: &a];
+
+  return ARGB_TO_ULONG((int)(a*255),
+                       (int)(r*255), (int)(g*255), (int)(b*255));
+}
 
 void
 ns_query_color(void *col, XColor *color_def, int setPixel)
diff --git a/src/xdisp.c b/src/xdisp.c
index a0113a05190..9a0752f2671 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -20287,7 +20287,7 @@ extend_face_to_end_of_line (struct it *it)
   if (FRAME_WINDOW_P (f)
       && MATRIX_ROW_DISPLAYS_TEXT_P (it->glyph_row)
       && face->box == FACE_NO_BOX
-      && face->background == FRAME_BACKGROUND_PIXEL (f)
+      && FACE_COLOR_TO_PIXEL (face->background, f) == FRAME_BACKGROUND_PIXEL (f)
 #ifdef HAVE_WINDOW_SYSTEM
       && !face->stipple
 #endif
@@ -20432,7 +20432,7 @@ extend_face_to_end_of_line (struct it *it)
 	  && (it->glyph_row->used[LEFT_MARGIN_AREA]
 	      < WINDOW_LEFT_MARGIN_WIDTH (it->w))
 	  && !it->glyph_row->mode_line_p
-	  && default_face->background != FRAME_BACKGROUND_PIXEL (f))
+	  && FACE_COLOR_TO_PIXEL (face->background, f) != FRAME_BACKGROUND_PIXEL (f))
 	{
 	  struct glyph *g = it->glyph_row->glyphs[LEFT_MARGIN_AREA];
 	  struct glyph *e = g + it->glyph_row->used[LEFT_MARGIN_AREA];
@@ -20473,7 +20473,7 @@ extend_face_to_end_of_line (struct it *it)
 	  && (it->glyph_row->used[RIGHT_MARGIN_AREA]
 	      < WINDOW_RIGHT_MARGIN_WIDTH (it->w))
 	  && !it->glyph_row->mode_line_p
-	  && default_face->background != FRAME_BACKGROUND_PIXEL (f))
+	  && FACE_COLOR_TO_PIXEL (face->background, f) != FRAME_BACKGROUND_PIXEL (f))
 	{
 	  struct glyph *g = it->glyph_row->glyphs[RIGHT_MARGIN_AREA];
 	  struct glyph *e = g + it->glyph_row->used[RIGHT_MARGIN_AREA];