diff --git a/src/modules/Image/encodings/bmp.c b/src/modules/Image/encodings/bmp.c
index 2791b61f92a3f87a08909acd572b8c9bd47a248a..3228b5cf0ae878b7d5df1323384f473c3b1ec302 100644
--- a/src/modules/Image/encodings/bmp.c
+++ b/src/modules/Image/encodings/bmp.c
@@ -466,6 +466,9 @@ void img_bmp_encode(INT32 args)
 	 s++;
 	 if (!l--)
 	 {
+#ifdef USE_VALGRIND
+	    MEMSET(c, 0, skip);
+#endif
 	    c+=skip;
 	    l=img->xsize-1;
 	 }