diff --git a/src/cairo-image-surface.c b/src/cairo-image-surface.c
index 87abf1696..36acc4f92 100644
--- a/src/cairo-image-surface.c
+++ b/src/cairo-image-surface.c
@@ -221,59 +221,55 @@ _pixman_format_from_masks (cairo_format_masks_t *masks,
 /* XXX: This function should really live inside pixman. */
 void
 _pixman_format_to_masks (pixman_format_code_t	 pixman_format,
-			 uint32_t		*bpp,
-			 uint32_t		*red,
-			 uint32_t		*green,
-			 uint32_t		*blue)
+			 cairo_format_masks_t	*masks)
 {
-    *red = 0x0;
-    *green = 0x0;
-    *blue = 0x0;
+    masks->red_mask   = 0x0;
+    masks->green_mask = 0x0;
+    masks->blue_mask  = 0x0;
 
     switch (pixman_format)
     {
     case PIXMAN_a8r8g8b8:
     case PIXMAN_x8r8g8b8:
     default:
-	*bpp   = 32;
-	*red   = 0x00ff0000;
-	*green = 0x0000ff00;
-	*blue  = 0x000000ff;
+	masks->bpp        = 32;
+	masks->red_mask   = 0x00ff0000;
+	masks->green_mask = 0x0000ff00;
+	masks->blue_mask  = 0x000000ff;
 	break;
 
     case PIXMAN_a8b8g8r8:
     case PIXMAN_x8b8g8r8:
-	*bpp   = 32;
-	*red   = 0x000000ff;
-	*green = 0x0000ff00;
-	*blue  = 0x00ff0000;
+	masks->bpp        = 32;
+	masks->red_mask   = 0x000000ff;
+	masks->green_mask = 0x0000ff00;
+	masks->blue_mask  = 0x00ff0000;
 	break;
 
     case PIXMAN_r5g6b5:
-	*bpp   = 16;
-	*red   = 0xf800;
-	*green = 0x07e0;
-	*blue  = 0x001f;
+	masks->bpp        = 16;
+	masks->red_mask   = 0xf800;
+	masks->green_mask = 0x07e0;
+	masks->blue_mask  = 0x001f;
 	break;
 
     case PIXMAN_x1r5g5b5:
-	*bpp   = 16;
-	*red   = 0x7c00;
-	*green = 0x03e0;
-	*blue  = 0x001f;
+	masks->bpp        = 16;
+	masks->red_mask   = 0x7c00;
+	masks->green_mask = 0x03e0;
+	masks->blue_mask  = 0x001f;
 	break;
 
     case PIXMAN_a8:
-	*bpp = 8;
+	masks->bpp = 8;
 	break;
 
     case PIXMAN_a1:
-	*bpp = 1;
+	masks->bpp = 1;
 	break;
     }
 }
 
-
 /* XXX: This function really should be eliminated. We don't really
  * want to advertise a cairo image surface that supports any possible
  * format. A minimal step would be to replace this function with one
diff --git a/src/cairo-xlib-surface.c b/src/cairo-xlib-surface.c
index cd1814b26..b8bea7ce5 100644
--- a/src/cairo-xlib-surface.c
+++ b/src/cairo-xlib-surface.c
@@ -735,11 +735,11 @@ _draw_image_surface (cairo_xlib_surface_t   *surface,
 		     int                    dst_y)
 {
     XImage ximage;
-    uint32_t bpp, red, green, blue;
+    cairo_format_masks_t image_masks;
     int native_byte_order = _native_byte_order_lsb () ? LSBFirst : MSBFirst;
     cairo_status_t status;
 
-    _pixman_format_to_masks (image->pixman_format, &bpp, &red, &green, &blue);
+    _pixman_format_to_masks (image->pixman_format, &image_masks);
     
     ximage.width = image->width;
     ximage.height = image->height;
@@ -751,10 +751,10 @@ _draw_image_surface (cairo_xlib_surface_t   *surface,
     ximage.bitmap_pad = 32;	/* always for libpixman */
     ximage.depth = image->depth;
     ximage.bytes_per_line = image->stride;
-    ximage.bits_per_pixel = bpp;
-    ximage.red_mask = red;
-    ximage.green_mask = green;
-    ximage.blue_mask = blue;
+    ximage.bits_per_pixel = image_masks.bpp;
+    ximage.red_mask = image_masks.red_mask;
+    ximage.green_mask = image_masks.green_mask;
+    ximage.blue_mask = image_masks.blue_mask;
     ximage.xoffset = 0;
 
     XInitImage (&ximage);
diff --git a/src/cairoint.h b/src/cairoint.h
index fdeeae591..84aa61bbc 100644
--- a/src/cairoint.h
+++ b/src/cairoint.h
@@ -1854,10 +1854,7 @@ _pixman_format_from_masks (cairo_format_masks_t *masks,
 
 cairo_private void
 _pixman_format_to_masks (pixman_format_code_t	 pixman_format,
-			 uint32_t		*bpp,
-			 uint32_t		*red,
-			 uint32_t		*green,
-			 uint32_t		*blue);
+			 cairo_format_masks_t	*masks);
 
 cairo_private cairo_surface_t *
 _cairo_image_surface_create_with_pixman_format (unsigned char		*data,