diff --git a/tools/tests/xen-access/xen-access.c b/tools/tests/xen-access/xen-access.c
index 9d960e2109..a081168dea 100644
--- a/tools/tests/xen-access/xen-access.c
+++ b/tools/tests/xen-access/xen-access.c
@@ -654,6 +654,8 @@ int main(int argc, char *argv[])
                 rc = xc_monitor_cpuid(xch, domain_id, 0);
             if ( desc_access )
                 rc = xc_monitor_descriptor_access(xch, domain_id, 0);
+            if ( write_ctrlreg_cr4 )
+                rc = xc_monitor_write_ctrlreg(xch, domain_id, VM_EVENT_X86_CR4, 0, 0, 0, 0);
 
             if ( privcall )
                 rc = xc_monitor_privileged_call(xch, domain_id, 0);