diff --git a/libavformat/img.c b/libavformat/img.c
index 70f6307d4d..139e0f48af 100644
--- a/libavformat/img.c
+++ b/libavformat/img.c
@@ -47,7 +47,7 @@ int emulate_frame_rate;
 
 static int image_probe(AVProbeData *p)
 {
-    if (filename_number_test(p->filename) >= 0)
+    if (filename_number_test(p->filename) >= 0 && guess_image_format(p->filename))
         return AVPROBE_SCORE_MAX;
     else
         return 0;
@@ -358,7 +358,7 @@ static AVOutputFormat imagepipe_oformat = {
     img_write_header,
     img_write_packet,
     img_write_trailer,
-    AVFMT_NEEDNUMBER | AVFMT_RAWPICTURE,
+    AVFMT_RAWPICTURE,
     img_set_parameters,
 };
 
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 2defc319d8..0db740333a 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -86,7 +86,9 @@ AVOutputFormat *guess_format(const char *short_name, const char *filename,
     int score_max, score;
 
     /* specific test for image sequences */
-    if (!short_name && filename && filename_number_test(filename) >= 0) {
+    if (!short_name && filename && 
+        filename_number_test(filename) >= 0 &&
+        guess_image_format(filename)) {
         return guess_format("image", NULL, NULL);
     }