diff --git a/mm/gup.c b/mm/gup.c
index ddde097..f1c1dae 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -515,7 +515,7 @@ static struct page *follow_p4d_mask(struct vm_area_struct *vma,
  * an error pointer if there is a mapping to something not represented
  * by a page descriptor (see also vm_normal_page()).
  */
-struct page *follow_page_mask(struct vm_area_struct *vma,
+static struct page *follow_page_mask(struct vm_area_struct *vma,
 			      unsigned long address, unsigned int flags,
 			      struct follow_page_context *ctx)
 {