diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 598c798cf871..f3a261c70d43 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -1616,7 +1616,7 @@ vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
 	/*
 	 * Check that the start and end points are not bogus.
 	 */
-	if (!vm_map_range_valid(map, start, end))
+	if (start == end || !vm_map_range_valid(map, start, end))
 		return (KERN_INVALID_ADDRESS);
 
 	/*