diff --git a/arch/x86/lib/iomap_copy_64.S b/arch/x86/lib/iomap_copy_64.S
index a9bdf0805be0..1329d7ca05b5 100644
--- a/arch/x86/lib/iomap_copy_64.S
+++ b/arch/x86/lib/iomap_copy_64.S
@@ -10,6 +10,6 @@
  */
 ENTRY(__iowrite32_copy)
 	movl %edx,%ecx
-	rep movsd
+	rep movsl
 	ret
 ENDPROC(__iowrite32_copy)