diff --git a/libavfilter/vf_null.c b/libavfilter/vf_null.c
index ad4095fb6d..9ddad6aead 100644
--- a/libavfilter/vf_null.c
+++ b/libavfilter/vf_null.c
@@ -18,7 +18,7 @@
 
 /**
  * @file libavfilter/vf_null.c
- * null filter
+ * null video filter
  */
 
 #include "avfilter.h"