diff --git a/third_party/libpng16/pngread.c b/third_party/libpng16/pngread.c
index 8fa7d9f16..5ab922403 100644
--- a/third_party/libpng16/pngread.c
+++ b/third_party/libpng16/pngread.c
@@ -3452,7 +3452,6 @@ png_image_read_background(png_voidp argument)
 
             for (pass = 0; pass < passes; ++pass)
             {
-               png_bytep row = png_voidcast(png_bytep, display->first_row);
                unsigned int     startx, stepx, stepy;
                png_uint_32      y;
 
@@ -3557,8 +3556,6 @@ png_image_read_background(png_voidp argument)
 
                         inrow += 2; /* gray and alpha channel */
                      }
-
-                     row += display->row_bytes;
                   }
                }
             }