diff --git a/openlp/core/ui/advancedtab.py b/openlp/core/ui/advancedtab.py
index 056374d46..6ca50de2b 100644
--- a/openlp/core/ui/advancedtab.py
+++ b/openlp/core/ui/advancedtab.py
@@ -416,6 +416,7 @@ class AdvancedTab(SettingsTab):
 
     def onDefaultServiceDayChanged(self, index):
         self.service_day = index
+        self.defaultServiceTime.setReadOnly(self.service_day == 7)
         self.updateServiceNameExample()
 
     def onDefaultServiceTimeChanged(self, time):