diff --git a/src/image.c b/src/image.c
index db50d94d4c1..fcfddd7f5dc 100644
--- a/src/image.c
+++ b/src/image.c
@@ -6346,7 +6346,7 @@ png_load (f, img)
      simple transparency, we prefer a clipping mask.  */
   if (!transparent_p)
     {
-      png_color_16 *image_bg;
+      /* png_color_16 *image_bg; */
       Lisp_Object specified_bg
 	= image_spec_value (img->spec, QCbackground, NULL);