diff --git a/tests/fate-run.sh b/tests/fate-run.sh
index bc1efa22d7..a16ce28a45 100755
--- a/tests/fate-run.sh
+++ b/tests/fate-run.sh
@@ -178,7 +178,7 @@ pcm(){
 fmtstdout(){
     fmt=$1
     shift 1
-    ffmpeg -bitexact "$@" -f $fmt -
+    ffmpeg -bitexact "$@" -bitexact -f $fmt -
 }
 
 enc_dec_pcm(){