diff --git a/examples/default/main.c b/examples/default/main.c
index 437d4c5bd4..87f5375082 100644
--- a/examples/default/main.c
+++ b/examples/default/main.c
@@ -53,8 +53,8 @@
 
 #ifdef MODULE_TRANSCEIVER
 
-char radio_stack_buffer[RADIO_STACK_SIZE];
-msg_t msg_q[RCV_BUFFER_SIZE];
+static char radio_stack_buffer[RADIO_STACK_SIZE];
+static msg_t msg_q[RCV_BUFFER_SIZE];
 
 void *radio(void *arg)
 {