diff --git a/src/tools/pw-cat.c b/src/tools/pw-cat.c
index f485a08f1..c81ae0f8c 100644
--- a/src/tools/pw-cat.c
+++ b/src/tools/pw-cat.c
@@ -1343,7 +1343,7 @@ static void format_from_filename(SF_INFO *info, const char *filename)
 		}
 	}
 	if (format == -1)
-		format = SF_FORMAT_WAV;
+		format = spa_streq(filename, "-") ? SF_FORMAT_AU : SF_FORMAT_WAV;
 	if (format == SF_FORMAT_WAV && info->channels > 2)
 		format = SF_FORMAT_WAVEX;