diff --git a/src/nm-serial-device.c b/src/nm-serial-device.c
index 99e365a24..061731014 100644
--- a/src/nm-serial-device.c
+++ b/src/nm-serial-device.c
@@ -19,7 +19,7 @@
 #include "nm-setting-ppp.h"
 #include "nm-utils.h"
 
-#define NM_DEBUG_SERIAL 1
+/* #define NM_DEBUG_SERIAL 1 */
 
 #define SERIAL_BUF_SIZE 2048