diff --git a/src/core/ipv4/autoip.c b/src/core/ipv4/autoip.c
index 53f8649e..2d2a1042 100644
--- a/src/core/ipv4/autoip.c
+++ b/src/core/ipv4/autoip.c
@@ -111,7 +111,7 @@ static void
 autoip_handle_arp_conflict(struct netif *netif)
 {
   /* Somehow detect if we are defending or retreating */
-  unsigned char defend = 1; // tbd
+  unsigned char defend = 1; /* tbd */
 
   if(defend) {
     if(netif->autoip->lastconflict > 0) {