diff --git a/debayer.cc b/debayer.cc
index 4c6f2bd..73fe9d8 100644
--- a/debayer.cc
+++ b/debayer.cc
@@ -13,7 +13,7 @@ void debayer_grbg16_simple (uint16_t * src, int src_w, int src_h,
   uint8_t r, g, b;
   int ys, yd, xs, xd;
 
-  for (ys = 0, yd = 0; ys < src_h; ys++) {
+  for (ys = 0, yd = 0; ys < src_h && yd < dst_h; ys++, yd++) {
     for (xs = 0, xd = 0; xs < src_w; xs++) {
 
       /* read the pixel but only the lower 8bit */
@@ -50,7 +50,6 @@ void debayer_grbg16_simple (uint16_t * src, int src_w, int src_h,
     /* if the source image is too small ignore the other places */
     if (xd < dst_w)
       dst += 3 * (dst_w - xd);
-    yd++;
   }
 }