diff --git a/xen/common/domain.c b/xen/common/domain.c
index b9f80bd2bb..3b1169d79b 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -1446,7 +1446,7 @@ int vcpu_reset(struct vcpu *v)
  * of memory, and it sets a pending event to make sure that a pending
  * event doesn't get missed.
  */
-int map_vcpu_info(struct vcpu *v, unsigned long gfn, unsigned offset)
+int map_vcpu_info(struct vcpu *v, unsigned long gfn, unsigned int offset)
 {
     struct domain *d = v->domain;
     void *mapping;
diff --git a/xen/include/xen/domain.h b/xen/include/xen/domain.h
index 1c3c88a14d..628b14b086 100644
--- a/xen/include/xen/domain.h
+++ b/xen/include/xen/domain.h
@@ -65,7 +65,7 @@ void cf_check free_pirq_struct(void *);
 int  arch_vcpu_create(struct vcpu *v);
 void arch_vcpu_destroy(struct vcpu *v);
 
-int map_vcpu_info(struct vcpu *v, unsigned long gfn, unsigned offset);
+int map_vcpu_info(struct vcpu *v, unsigned long gfn, unsigned int offset);
 void unmap_vcpu_info(struct vcpu *v);
 
 int arch_domain_create(struct domain *d,