diff --git a/src/app_main.c b/src/app_main.c
index 874a246..91ad5d4 100644
--- a/src/app_main.c
+++ b/src/app_main.c
@@ -162,6 +162,9 @@ void UserMain(void)
         printf("FATAL: unknown board %s\r\n", NINLIGHT_DEVICE_ID);
         return;
     }
-    tls_os_mutex_create(0, &s_lock);
+    if (tls_os_mutex_create(0, &s_lock) != TLS_OS_SUCCESS) {
+        printf("FATAL: cannot create app lock\r\n");
+        return;
+    }
     tls_os_task_create(NULL, "nl_app", app_task, NULL, (u8 *)s_app_stack, sizeof(s_app_stack), NL_APP_PRIO, 0);
 }