diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c
index a90499c087f0..2ee7b5a5016c 100644
--- a/arch/s390/pci/pci_mmio.c
+++ b/arch/s390/pci/pci_mmio.c
@@ -223,7 +223,7 @@ static inline int __pcilg_mio_inuser(
 		[ioaddr_len] "+&d" (ioaddr_len.pair),
 		[cc] "+d" (cc), [val] "=d" (val),
 		[dst] "+a" (dst), [cnt] "+d" (cnt), [tmp] "=d" (tmp),
-		[shift] "+d" (shift)
+		[shift] "+a" (shift)
 		:: "cc", "memory");
 
 	/* did we write everything to the user space buffer? */