diff --git a/libavcodec/h264dec.h b/libavcodec/h264dec.h
index 0b9c5784a2..9a1ec1bace 100644
--- a/libavcodec/h264dec.h
+++ b/libavcodec/h264dec.h
@@ -168,7 +168,7 @@ typedef struct H264Ref {
 } H264Ref;
 
 typedef struct H264SliceContext {
-    struct H264Context *h264;
+    const struct H264Context *h264;
     GetBitContext gb;
     ERContext *er;