diff --git a/src/core/ipv4/dhcp.c b/src/core/ipv4/dhcp.c
index 9bf70ec8..06a24b71 100644
--- a/src/core/ipv4/dhcp.c
+++ b/src/core/ipv4/dhcp.c
@@ -1889,7 +1889,7 @@ dhcp_option_trailer(struct dhcp *dhcp)
  *         0 otherwise
  */
 u8_t
-dhcp_supplied_address(struct netif *netif)
+dhcp_supplied_address(const struct netif *netif)
 {
   if ((netif != NULL) && (netif->dhcp != NULL)) {
     if ((netif->dhcp->state == DHCP_STATE_BOUND) ||
diff --git a/src/include/lwip/dhcp.h b/src/include/lwip/dhcp.h
index bbd72a7e..579bc98b 100644
--- a/src/include/lwip/dhcp.h
+++ b/src/include/lwip/dhcp.h
@@ -159,7 +159,7 @@ void dhcp_arp_reply(struct netif *netif, const ip4_addr_t *addr);
 #endif
 
 /** check if DHCP supplied netif->ip_addr */
-u8_t dhcp_supplied_address(struct netif *netif);
+u8_t dhcp_supplied_address(const struct netif *netif);
 
 /** to be called every minute */
 void dhcp_coarse_tmr(void);