diff --git a/applets/systemmonitor/common/contents/ui/ConfigGeneral.qml b/applets/systemmonitor/common/contents/ui/ConfigGeneral.qml
index 3f025ffaf..3e8f679ef 100644
--- a/applets/systemmonitor/common/contents/ui/ConfigGeneral.qml
+++ b/applets/systemmonitor/common/contents/ui/ConfigGeneral.qml
@@ -160,8 +160,10 @@ Item {
                             }
                         } else {
                             var idx = cfg_sources.indexOf(model.source);
-                            if (idx !== -1) {
-                                cfg_sources.splice(idx, 1);
+                            if (cfg_sources.length !== 1) { // This condition prohibits turning off the last item from the list.
+                                if (idx !== -1) {
+                                    cfg_sources.splice(idx, 1);
+                                }
                             }
                         }
                         cfg_sourcesChanged();