diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c
index 84868904df..51f2a7c1a3 100644
--- a/libavcodec/vc1.c
+++ b/libavcodec/vc1.c
@@ -4601,7 +4601,7 @@ static int vc1_parse(AVCodecParserContext *s,
     return next;
 }
 
-int vc1_split(AVCodecContext *avctx,
+static int vc1_split(AVCodecContext *avctx,
                            const uint8_t *buf, int buf_size)
 {
     int i;