diff --git a/libavformat/internal.h b/libavformat/internal.h
index 3dd1fb1a91..0dfbf02ca0 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -624,22 +624,6 @@ void ff_format_set_url(AVFormatContext *s, char *url);
  */
 int ff_match_url_ext(const char *url, const char *extensions);
 
-/**
- * Return in 'buf' the path with '%d' replaced by a number.
- *
- * Also handles the '%0nd' format where 'n' is the total number
- * of digits and '%%'.
- *
- * @param buf destination buffer
- * @param buf_size destination buffer size
- * @param path path with substitution template
- * @param number the number to substitute
- * @param flags AV_FRAME_FILENAME_FLAGS_*
- * @return 0 if OK, -1 on format error
- */
-int ff_get_frame_filename(char *buf, int buf_size, const char *path,
-                          int64_t number, int flags);
-
 /**
  * Return in 'buf' the path with '%d' replaced by a number.
  *
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 336fb556f3..8a249ad85a 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -334,7 +334,7 @@ fail:
     return AVERROR(EINVAL);
 }
 
-int ff_get_frame_filename(char *buf, int buf_size, const char *path, int64_t number, int flags)
+static int get_frame_filename(char *buf, int buf_size, const char *path, int64_t number, int flags)
 {
     AVBPrint bp;
     av_bprint_init_for_buffer(&bp, buf, buf_size);
@@ -343,12 +343,12 @@ int ff_get_frame_filename(char *buf, int buf_size, const char *path, int64_t num
 
 int av_get_frame_filename2(char *buf, int buf_size, const char *path, int number, int flags)
 {
-    return ff_get_frame_filename(buf, buf_size, path, number, flags);
+    return get_frame_filename(buf, buf_size, path, number, flags);
 }
 
 int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
 {
-    return ff_get_frame_filename(buf, buf_size, path, number, 0);
+    return get_frame_filename(buf, buf_size, path, number, 0);
 }
 
 void av_url_split(char *proto, int proto_size,