diff --git a/avconv.c b/avconv.c
index 7aacbe0da7..3eb249dcee 100644
--- a/avconv.c
+++ b/avconv.c
@@ -3350,6 +3350,7 @@ static int copy_metadata(char *outspec, char *inspec, AVFormatContext *oc, AVFor
             METADATA_CHECK_INDEX(index, context->nb_programs, "program")\
             meta = &context->programs[index]->metadata;\
             break;\
+        default: av_assert0(0);\
         }\
 
     SET_DICT(type_in, meta_in, ic, idx_in);