diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index a1606deaca..f78b335816 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -130,7 +130,7 @@ PropertyInfo qdev_prop_bit = {
 static uint64_t qdev_get_prop_mask64(Property *prop)
 {
     assert(prop->info == &qdev_prop_bit);
-    return 0x1 << prop->bitnr;
+    return 0x1ull << prop->bitnr;
 }
 
 static void bit64_prop_set(DeviceState *dev, Property *props, bool val)