diff --git a/common/rfb/tightDecode.h b/common/rfb/tightDecode.h
index e604e0e..e9f5f6b 100644
--- a/common/rfb/tightDecode.h
+++ b/common/rfb/tightDecode.h
@@ -185,7 +185,7 @@
         }
       } else {
         while (h > 0) {
-          memcpy(ptr, srcPtr, rowSize * sizeof(PIXEL_T));
+          memcpy(ptr, srcPtr, w * sizeof(PIXEL_T));
           ptr += stride;
           srcPtr += w * sizeof(PIXEL_T);
           h--;