diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -2247,8 +2247,15 @@
 		rv = vm_map_insert(map, object, offset, *addr, *addr + length,
 		    prot, max, cow);
 	}
-	if (rv == KERN_SUCCESS && update_anon)
-		map->anon_loc = *addr + length;
+
+	/*
+	 * Update the starting address for clustered anonymous memory mappings
+	 * if a starting address was not previously defined or an ASLR restart
+	 * placed an anonymous memory mapping at a lower address.
+	 */
+	if (update_anon && rv == KERN_SUCCESS && (map->anon_loc == 0 ||
+	    *addr < map->anon_loc))
+		map->anon_loc = *addr;
 done:
 	vm_map_unlock(map);
 	return (rv);
@@ -4041,9 +4048,6 @@
 		    entry->object.vm_object != NULL)
 			pmap_map_delete(map->pmap, entry->start, entry->end);
 
-		if (entry->end == map->anon_loc)
-			map->anon_loc = entry->start;
-
 		/*
 		 * Delete the entry only after removing all pmap
 		 * entries pointing to its pages.  (Otherwise, its