diff --git a/epan/dissectors/packet-ieee80211-radiotap-iter.c b/epan/dissectors/packet-ieee80211-radiotap-iter.c

index 56ca297434..4006637fb2 100644

--- a/epan/dissectors/packet-ieee80211-radiotap-iter.c

+++ b/epan/dissectors/packet-ieee80211-radiotap-iter.c

@@ -131,6 +131,7 @@ int ieee80211_radiotap_iterator_init(

 	iterator->_bitmap_shifter = get_unaligned_le32(&radiotap_header->it_present);

 	iterator->_arg = (guint8 *)radiotap_header + sizeof(*radiotap_header);

 	iterator->_reset_on_ext = 0;

+	iterator->_next_ns_data = NULL;

 	iterator->_next_bitmap = &radiotap_header->it_present;

 	iterator->_next_bitmap++;

 	iterator->_vns = vns;

@@ -287,9 +288,14 @@ int ieee80211_radiotap_iterator_next(

 			}

 			if (!align) {

 				/* skip all subsequent data */

+				if (!iterator->_next_ns_data)

+					return -EINVAL;

 				iterator->_arg = iterator->_next_ns_data;

 				/* give up on this namespace */

 				iterator->current_namespace = NULL;

+				iterator->_next_ns_data = NULL;

+				if (!ITERATOR_VALID(iterator, 0))

+					return -EINVAL;

 				goto next_entry;

 			}

 			break;