diff --git a/src/core/ipv4/dhcp.c b/src/core/ipv4/dhcp.c
index 5e62b2af..7ae7422e 100644
--- a/src/core/ipv4/dhcp.c
+++ b/src/core/ipv4/dhcp.c
@@ -719,6 +719,8 @@ dhcp_set_struct(struct netif *netif, struct dhcp *dhcp)
 
   /* clear data structure */
   memset(dhcp, 0, sizeof(struct dhcp));
+  /* mark this as externally allocated */
+  dhcp->flags |= DHCP_FLAG_EXTERNAL_MEM;
   /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */
   netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp);
 }
@@ -734,11 +736,15 @@ dhcp_set_struct(struct netif *netif, struct dhcp *dhcp)
  */
 void dhcp_cleanup(struct netif *netif)
 {
+  struct dhcp *dhcp;
   LWIP_ASSERT_CORE_LOCKED();
   LWIP_ASSERT("netif != NULL", netif != NULL);
 
-  if (netif_dhcp_data(netif) != NULL) {
-    mem_free(netif_dhcp_data(netif));
+  dhcp = netif_dhcp_data(netif);
+  if (dhcp != NULL) {
+    if (!(dhcp->flags & DHCP_FLAG_EXTERNAL_MEM)) {
+      mem_free(dhcp);
+    }
     netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, NULL);
   }
 }
diff --git a/src/include/lwip/dhcp.h b/src/include/lwip/dhcp.h
index 1a3bba01..4f69dfcb 100644
--- a/src/include/lwip/dhcp.h
+++ b/src/include/lwip/dhcp.h
@@ -63,6 +63,7 @@ extern "C" {
 #define DHCP_BOOT_FILE_LEN      128U
 
 #define DHCP_FLAG_SUBNET_MASK_GIVEN 0x01
+#define DHCP_FLAG_EXTERNAL_MEM      0x02
 
 /* AutoIP cooperation flags (struct dhcp.autoip_coop_state) */
 typedef enum {