diff --git a/mm/mlock.c b/mm/mlock.c
index b1fec89..145a425 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -516,6 +516,7 @@
 	int nr_pages;
 	int ret = 0;
 	int lock = !!(newflags & VM_LOCKED);
+	vm_flags_t old_flags = vma->vm_flags;
 
 	if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) ||
 	    is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm))
@@ -550,6 +551,8 @@
 	nr_pages = (end - start) >> PAGE_SHIFT;
 	if (!lock)
 		nr_pages = -nr_pages;
+	else if (old_flags & VM_LOCKED)
+		nr_pages = 0;
 	mm->locked_vm += nr_pages;
 
 	/*