diff --git a/src/widgets/util/qcompleter_p.h b/src/widgets/util/qcompleter_p.h
index b100f24f9b..afcdfe7aa2 100644
--- a/src/widgets/util/qcompleter_p.h
+++ b/src/widgets/util/qcompleter_p.h
@@ -122,7 +122,7 @@ private:
 };
 
 struct QMatchData {
-    QMatchData() : exactMatchIndex(-1) { }
+    QMatchData() : exactMatchIndex(-1), partial(false) { }
     QMatchData(const QIndexMapper& indices, int em, bool p) :
         indices(indices), exactMatchIndex(em), partial(p) { }
     QIndexMapper indices;