diff --git a/avconv_filter.c b/avconv_filter.c
index cad68e2da3..2065cb008b 100644
--- a/avconv_filter.c
+++ b/avconv_filter.c
@@ -41,7 +41,7 @@ static char *choose_ ## var ## s(OutputStream *ost)                            \
     if (ost->st->codec->var != none) {                                         \
         get_name(ost->st->codec->var);                                         \
         return av_strdup(name);                                                \
-    } else if (ost->enc->supported_list) {                                     \
+    } else if (ost->enc && ost->enc->supported_list) {                         \
         const type *p;                                                         \
         AVIOContext *s = NULL;                                                 \
         uint8_t *ret;                                                          \