diff --git a/arch/arm/include/asm/xen/interface.h b/arch/arm/include/asm/xen/interface.h
index ae05e56dd17d..62160f259b0e 100644
--- a/arch/arm/include/asm/xen/interface.h
+++ b/arch/arm/include/asm/xen/interface.h
@@ -31,7 +31,9 @@
 /* Explicitly size integers that represent pfns in the interface with
  * Xen so that we can have one ABI that works for 32 and 64 bit guests. */
 typedef uint64_t xen_pfn_t;
+#define PRI_xen_pfn "llx"
 typedef uint64_t xen_ulong_t;
+#define PRI_xen_ulong "llx"
 /* Guest handles for primitive C types. */
 __DEFINE_GUEST_HANDLE(uchar, unsigned char);
 __DEFINE_GUEST_HANDLE(uint,  unsigned int);
diff --git a/arch/x86/include/asm/xen/interface.h b/arch/x86/include/asm/xen/interface.h
index 28fc6211a79a..c5b13e76d730 100644
--- a/arch/x86/include/asm/xen/interface.h
+++ b/arch/x86/include/asm/xen/interface.h
@@ -51,7 +51,9 @@
  * with Xen so that on ARM we can have one ABI that works for 32 and 64
  * bit guests. */
 typedef unsigned long xen_pfn_t;
+#define PRI_xen_pfn "lx"
 typedef unsigned long xen_ulong_t;
+#define PRI_xen_ulong "lx"
 /* Guest handles for primitive C types. */
 __DEFINE_GUEST_HANDLE(uchar, unsigned char);
 __DEFINE_GUEST_HANDLE(uint,  unsigned int);
diff --git a/drivers/xen/sys-hypervisor.c b/drivers/xen/sys-hypervisor.c
index 66a0a1475acf..96453f8a85c5 100644
--- a/drivers/xen/sys-hypervisor.c
+++ b/drivers/xen/sys-hypervisor.c
@@ -285,7 +285,8 @@ static ssize_t virtual_start_show(struct hyp_sysfs_attr *attr, char *buffer)
 		ret = HYPERVISOR_xen_version(XENVER_platform_parameters,
 					     parms);
 		if (!ret)
-			ret = sprintf(buffer, "%lx\n", parms->virt_start);
+			ret = sprintf(buffer, "%"PRI_xen_ulong"\n",
+				      parms->virt_start);
 		kfree(parms);
 	}