diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
index dfa2d2b220..f8fc483bd9 100644
--- a/libavfilter/avfilter.c
+++ b/libavfilter/avfilter.c
@@ -410,7 +410,7 @@ static int pad_count(const AVFilterPad *pads)
     return count;
 }
 
-static char *default_filter_name(void *filter_ctx)
+static const char *default_filter_name(void *filter_ctx)
 {
     AVFilterContext *ctx = filter_ctx;
     return ctx->name ? ctx->name : ctx->filter->name;