diff --git a/src/plugins/cppeditor/cppeditor.cpp b/src/plugins/cppeditor/cppeditor.cpp
index 1feece042db..ef13ed5de7f 100644
--- a/src/plugins/cppeditor/cppeditor.cpp
+++ b/src/plugins/cppeditor/cppeditor.cpp
@@ -196,6 +196,12 @@ void CPPEditor::createToolBar(CPPEditorEditable *editable)
     m_methodCombo = new QComboBox;
     m_methodCombo->setMinimumContentsLength(22);
     m_methodCombo->setSizeAdjustPolicy(QComboBox::AdjustToContents);
+
+    // Make the combo box prefer to expand
+    QSizePolicy policy = m_methodCombo->sizePolicy();
+    policy.setHorizontalPolicy(QSizePolicy::Expanding);
+    m_methodCombo->setSizePolicy(policy);
+
     QTreeView *methodView = new OverviewTreeView();
     methodView->header()->hide();
     methodView->setItemsExpandable(false);