diff --git a/libavcodec/msrledec.c b/libavcodec/msrledec.c
index 06777d7fd4..4d3da5ba17 100644
--- a/libavcodec/msrledec.c
+++ b/libavcodec/msrledec.c
@@ -211,8 +211,8 @@ static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic,
             switch(depth){
             case  8:
                 pix[0] = bytestream2_get_byte(gb);
-                for(i = 0; i < p1; i++)
-                        *output++ = pix[0];
+                memset(output, pix[0], p1);
+                output += p1;
                 break;
             case 16:
                 pix16  = bytestream2_get_le16(gb);