diff --git a/libavcodec/mmvideo.c b/libavcodec/mmvideo.c
index 9ff6393aec..9a7c10c3ab 100644
--- a/libavcodec/mmvideo.c
+++ b/libavcodec/mmvideo.c
@@ -49,7 +49,7 @@
 typedef struct MmContext {
     AVCodecContext *avctx;
     AVFrame *frame;
-    int palette[AVPALETTE_COUNT];
+    unsigned int palette[AVPALETTE_COUNT];
     GetByteContext gb;
 } MmContext;