diff --git a/kernel/tests.c b/kernel/tests.c
index fe4ae8ac..6f1fb2af 100644
--- a/kernel/tests.c
+++ b/kernel/tests.c
@@ -181,7 +181,7 @@ void* server_task(void* e)
 
             err = srv_sendBuffer(&srv,0,buff,sizeof(buff));
             if ( err < 0)
-                    SHELLDEBUGPRINTF("err: % d", err);
+                    SHELLDEBUGPRINTF("err: %d", err);
 
             if (!(i%100))
                 SHELLDEBUGPRINTF("\r-%d-",i);