diff --git a/fs/dax.c b/fs/dax.c
index 5c548d8..3220da7 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -578,8 +578,10 @@
 		return VM_FAULT_FALLBACK;
 
 	/* Fall back to PTEs if we're going to COW */
-	if (write && !(vma->vm_flags & VM_SHARED))
+	if (write && !(vma->vm_flags & VM_SHARED)) {
+		split_huge_pmd(vma, pmd, address);
 		return VM_FAULT_FALLBACK;
+	}
 	/* If the PMD would extend outside the VMA */
 	if (pmd_addr < vma->vm_start)
 		return VM_FAULT_FALLBACK;