diff --git a/libavfilter/tests/filtfmts.c b/libavfilter/tests/filtfmts.c
index cc04654222..6bd8237e31 100644
--- a/libavfilter/tests/filtfmts.c
+++ b/libavfilter/tests/filtfmts.c
@@ -28,7 +28,7 @@
 
 int main(int argc, char **argv)
 {
-    AVFilter *filter;
+    const AVFilter *filter;
     AVFilterContext *filter_ctx;
     AVFilterGraph *graph_ctx;
     const char *filter_name;