diff --git a/src/photo.c b/src/photo.c
index 0ffa566..3128e22 100644
--- a/src/photo.c
+++ b/src/photo.c
@@ -140,6 +140,10 @@ void cammy_photo_dither(uint8_t *dest,
                             int  width,
                             int  height,
                             int  stride) {
+    static uint8_t values[4] = {
+        0, 86, 171, 255
+    };
+
     size_t x, y;
 
     for (y=0; y<height; y++) {
@@ -164,9 +168,11 @@ void cammy_photo_dither(uint8_t *dest,
                 value = from ^ 0x03;
             }
 
-            dest[stride*CAMMY_PHOTO_WIDTH*y+stride*x]   = value;
-            dest[stride*CAMMY_PHOTO_WIDTH*y+stride*x+1] = value;
-            dest[stride*CAMMY_PHOTO_WIDTH*y+stride*x+2] = value;
+            value ^= 3;
+
+            dest[stride*width*y+stride*x]   = values[value];
+            dest[stride*width*y+stride*x+1] = values[value];
+            dest[stride*width*y+stride*x+2] = values[value];
         }
     }
 }