diff --git a/src/core/ipv4/igmp.c b/src/core/ipv4/igmp.c
index 164a3bf1..ef3b8ab9 100644
--- a/src/core/ipv4/igmp.c
+++ b/src/core/ipv4/igmp.c
@@ -104,7 +104,7 @@ static void   igmp_delaying_member(struct igmp_group *group, u8_t maxresp);
 static err_t  igmp_ip_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, struct netif *netif);
 static void   igmp_send(struct igmp_group *group, u8_t type);
 
-static struct igmp_group* igmp_group_list;
+struct igmp_group* igmp_group_list;
 static ip4_addr_t     allsystems;
 static ip4_addr_t     allrouters;
 
diff --git a/src/core/ipv6/mld6.c b/src/core/ipv6/mld6.c
index 9ae44c06..09fe2a26 100644
--- a/src/core/ipv6/mld6.c
+++ b/src/core/ipv6/mld6.c
@@ -77,7 +77,7 @@
 
 
 /* The list of joined groups. */
-static struct mld_group* mld_group_list;
+struct mld_group* mld_group_list;
 
 
 /* Forward declarations. */
diff --git a/src/include/lwip/igmp.h b/src/include/lwip/igmp.h
index be78c332..6b46bbcc 100644
--- a/src/include/lwip/igmp.h
+++ b/src/include/lwip/igmp.h
@@ -88,6 +88,9 @@ struct igmp_group {
   u8_t               use;
 };
 
+/* Head of IGMP group list */
+extern struct igmp_group* igmp_group_list;
+
 /*  Prototypes */
 void   igmp_init(void);
 err_t  igmp_start(struct netif *netif);
diff --git a/src/include/lwip/mld6.h b/src/include/lwip/mld6.h
index 089974ae..02637e8b 100644
--- a/src/include/lwip/mld6.h
+++ b/src/include/lwip/mld6.h
@@ -72,6 +72,9 @@ struct mld_group {
   u8_t               use;
 };
 
+/* Head of MLD group list */
+extern struct mld_group* mld_group_list;
+
 #define MLD6_TMR_INTERVAL              100 /* Milliseconds */
 
 err_t  mld6_stop(struct netif *netif);