diff --git a/sys/net/sixlowpan/flowcontrol.h b/sys/net/sixlowpan/flowcontrol.h
index cf7f811248..b14b7387bf 100644
--- a/sys/net/sixlowpan/flowcontrol.h
+++ b/sys/net/sixlowpan/flowcontrol.h
@@ -39,7 +39,7 @@
 #define BORDER_RWS                (1)
 #define BORDER_SL_TIMEOUT         (500) // microseconds, maybe smaller
 
-#define SENDING_SLOT_STACK_SIZE     (256)
+#define SENDING_SLOT_STACK_SIZE     (MINIMUM_STACK_SIZE + 256)
 
 typedef struct {
     /* Sender state */