diff --git a/net/mld/mld.h b/net/mld/mld.h
index 50b5ebb99e4..c67711c50cc 100644
--- a/net/mld/mld.h
+++ b/net/mld/mld.h
@@ -330,6 +330,16 @@ FAR struct mld_group_s *mld_grpallocfind(FAR struct net_driver_s *dev,
 void mld_grpfree(FAR struct net_driver_s *dev,
                  FAR struct mld_group_s *group);
 
+/****************************************************************************
+ * Name:  mld_grpfree_all
+ *
+ * Description:
+ *   Release all previously allocated groups for a device.
+ *
+ ****************************************************************************/
+
+void mld_grpfree_all(FAR struct net_driver_s *dev);
+
 /****************************************************************************
  * Name:  mld_new_pollcycle
  *
diff --git a/net/mld/mld_group.c b/net/mld/mld_group.c
index 588de815665..d5152f21970 100644
--- a/net/mld/mld_group.c
+++ b/net/mld/mld_group.c
@@ -285,4 +285,29 @@ void mld_new_pollcycle(FAR struct net_driver_s *dev)
 }
 #endif
 
+/****************************************************************************
+ * Name:  mld_grpfree_all
+ *
+ * Description:
+ *   Release all previously allocated groups for a device.
+ *
+ * Assumptions:
+ *   The network is locked.
+ *
+ ****************************************************************************/
+
+void mld_grpfree_all(FAR struct net_driver_s *dev)
+{
+  FAR struct mld_group_s *group =
+                         (FAR struct mld_group_s *)dev->d_mld.grplist.head;
+  FAR struct mld_group_s *next;
+
+  while (group != NULL)
+    {
+      next = group->next;
+      mld_grpfree(dev, group);
+      group = next;
+    }
+}
+
 #endif /* CONFIG_NET_MLD */
diff --git a/net/netdev/netdev_unregister.c b/net/netdev/netdev_unregister.c
index fea06799588..57f59a9dee2 100644
--- a/net/netdev/netdev_unregister.c
+++ b/net/netdev/netdev_unregister.c
@@ -37,6 +37,7 @@
 #include <net/ethernet.h>
 #include <nuttx/net/netdev.h>
 
+#include "mld/mld.h"
 #include "utils/utils.h"
 #include "netdev/netdev.h"
 
@@ -150,6 +151,16 @@ int netdev_unregister(FAR struct net_driver_s *dev)
 #ifdef CONFIG_NETDEV_IFINDEX
       free_ifindex(dev->d_ifindex);
 #endif
+
+#ifdef CONFIG_NET_MLD
+      if ((dev->d_flags & IFF_MULTICAST) != 0)
+        {
+          /* MLD is only supported on multicast capable devices */
+
+          mld_grpfree_all(dev);
+        }
+#endif
+
       net_unlock();
 
 #if CONFIG_NETDEV_STATISTICS_LOG_PERIOD > 0