diff --git a/ffmpeg.c b/ffmpeg.c
index 7f17566247..11350ae4f1 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -3361,14 +3361,14 @@ static void opt_output_file(const char *filename)
     }
 
     if (last_asked_format) {
-        file_oformat = guess_format(last_asked_format, NULL, NULL);
+        file_oformat = av_guess_format(last_asked_format, NULL, NULL);
         if (!file_oformat) {
             fprintf(stderr, "Requested output format '%s' is not a suitable output format\n", last_asked_format);
             av_exit(1);
         }
         last_asked_format = NULL;
     } else {
-        file_oformat = guess_format(NULL, filename, NULL);
+        file_oformat = av_guess_format(NULL, filename, NULL);
         if (!file_oformat) {
             fprintf(stderr, "Unable to find a suitable output format for '%s'\n",
                     filename);
diff --git a/ffserver.c b/ffserver.c
index 23665a1e22..e545c060ed 100644
--- a/ffserver.c
+++ b/ffserver.c
@@ -3170,7 +3170,7 @@ static int rtp_new_av_stream(HTTPContext *c,
     ctx = avformat_alloc_context();
     if (!ctx)
         return -1;
-    ctx->oformat = guess_format("rtp", NULL, NULL);
+    ctx->oformat = av_guess_format("rtp", NULL, NULL);
 
     st = av_mallocz(sizeof(AVStream));
     if (!st)
@@ -3734,14 +3734,14 @@ static int ffserver_opt_default(const char *opt, const char *arg,
 static AVOutputFormat *ffserver_guess_format(const char *short_name, const char *filename,
                                              const char *mime_type)
 {
-    AVOutputFormat *fmt = guess_format(short_name, filename, mime_type);
+    AVOutputFormat *fmt = av_guess_format(short_name, filename, mime_type);
 
     if (fmt) {
         AVOutputFormat *stream_fmt;
         char stream_format_name[64];
 
         snprintf(stream_format_name, sizeof(stream_format_name), "%s_stream", fmt->name);
-        stream_fmt = guess_format(stream_format_name, NULL, NULL);
+        stream_fmt = av_guess_format(stream_format_name, NULL, NULL);
 
         if (stream_fmt)
             fmt = stream_fmt;
@@ -3880,7 +3880,7 @@ static int parse_ffconfig(const char *filename)
                     }
                 }
 
-                feed->fmt = guess_format("ffm", NULL, NULL);
+                feed->fmt = av_guess_format("ffm", NULL, NULL);
                 /* defaut feed file */
                 snprintf(feed->feed_filename, sizeof(feed->feed_filename),
                          "/tmp/%s.ffm", feed->filename);
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 79c5a1d36b..a4c7219e1e 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -201,7 +201,7 @@ AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
     if (!short_name && filename &&
         av_filename_number_test(filename) &&
         av_guess_image2_codec(filename) != CODEC_ID_NONE) {
-        return guess_format("image2", NULL, NULL);
+        return av_guess_format("image2", NULL, NULL);
     }
 #endif
     /* Find the proper file type. */
@@ -231,14 +231,14 @@ AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
 AVOutputFormat *guess_stream_format(const char *short_name, const char *filename,
                              const char *mime_type)
 {
-    AVOutputFormat *fmt = guess_format(short_name, filename, mime_type);
+    AVOutputFormat *fmt = av_guess_format(short_name, filename, mime_type);
 
     if (fmt) {
         AVOutputFormat *stream_fmt;
         char stream_format_name[64];
 
         snprintf(stream_format_name, sizeof(stream_format_name), "%s_stream", fmt->name);
-        stream_fmt = guess_format(stream_format_name, NULL, NULL);
+        stream_fmt = av_guess_format(stream_format_name, NULL, NULL);
 
         if (stream_fmt)
             fmt = stream_fmt;