2 files changed, 2 insertions, 1 deletions
diff --git a/src/corelib/json/qjsonarray.cpp b/src/corelib/json/qjsonarray.cpp
index 77a3d0a2b8..dd27603d6d 100644
--- a/src/corelib/json/qjsonarray.cpp
+++ b/src/corelib/json/qjsonarray.cpp
@@ -271,6 +271,7 @@ QVariantList QJsonArray::toVariantList() const
     QVariantList list;
 
     if (a) {
+        list.reserve(a->length);
         for (int i = 0; i < (int)a->length; ++i)
             list.append(QJsonValue(d, a, a->at(i)).toVariant());
     }
diff --git a/src/corelib/json/qjsonobject.cpp b/src/corelib/json/qjsonobject.cpp
index ae44cd9ff9..b7dfe88434 100644
--- a/src/corelib/json/qjsonobject.cpp
+++ b/src/corelib/json/qjsonobject.cpp
@@ -274,7 +274,7 @@ QStringList QJsonObject::keys() const
         return QStringList();
 
     QStringList keys;
-
+    keys.reserve(o->length);
     for (uint i = 0; i < o->length; ++i) {
         QJsonPrivate::Entry *e = o->entryAt(i);
         keys.append(e->key());