diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index d34d5813d006..777362cb4ea8 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -241,7 +241,7 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 /* combine single writes by using store-block insn */
 void __iowrite64_copy(void __iomem *to, const void *from, size_t count)
 {
-       zpci_memcpy_toio(to, from, count);
+	zpci_memcpy_toio(to, from, count * 8);
 }
 
 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,