diff --git a/xen/include/asm-x86/shadow.h b/xen/include/asm-x86/shadow.h
index de09e8168d..c720008425 100644
--- a/xen/include/asm-x86/shadow.h
+++ b/xen/include/asm-x86/shadow.h
@@ -215,8 +215,8 @@ void pv_l1tf_tasklet(unsigned long data);
 static inline void pv_l1tf_domain_init(struct domain *d)
 {
     d->arch.pv_domain.check_l1tf =
-        opt_pv_l1tf & (is_hardware_domain(d)
-                       ? OPT_PV_L1TF_DOM0 : OPT_PV_L1TF_DOMU);
+        !!(opt_pv_l1tf & (is_hardware_domain(d)
+                          ? OPT_PV_L1TF_DOM0 : OPT_PV_L1TF_DOMU));
 
 #ifdef CONFIG_SHADOW_PAGING
     tasklet_init(&d->arch.paging.shadow.pv_l1tf_tasklet,