diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c
index bc860f4373..ec95445696 100644
--- a/hw/xen/xen-mapcache.c
+++ b/hw/xen/xen-mapcache.c
@@ -491,18 +491,23 @@ static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc,
         return;
     }
     entry->lock--;
-    if (entry->lock > 0 || pentry == NULL) {
+    if (entry->lock > 0) {
         return;
     }
 
-    pentry->next = entry->next;
     ram_block_notify_remove(entry->vaddr_base, entry->size, entry->size);
     if (munmap(entry->vaddr_base, entry->size) != 0) {
         perror("unmap fails");
         exit(-1);
     }
+
     g_free(entry->valid_mapping);
-    g_free(entry);
+    if (pentry) {
+        pentry->next = entry->next;
+        g_free(entry);
+    } else {
+        memset(entry, 0, sizeof *entry);
+    }
 }
 
 typedef struct XenMapCacheData {