diff --git a/audio_stdout.c b/audio_stdout.c
index 61b8e6b1..cb11a99a 100644
--- a/audio_stdout.c
+++ b/audio_stdout.c
@@ -38,7 +38,7 @@
 
 static int fd = -1;
 
-static void start(int sample_rate int sample_format) {
+static void start(int sample_rate, int sample_format) {
   fd = STDOUT_FILENO;
 }