diff --git a/mm/mmap.c b/mm/mmap.c
index 6c561ac..a089cca8 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2634,6 +2634,7 @@
 
 	return 0;
 }
+EXPORT_SYMBOL(do_munmap);
 
 int vm_munmap(unsigned long start, size_t len)
 {