diff --git a/Widgets/AlignMeshesToolbox.hh b/Widgets/AlignMeshesToolbox.hh
index 7fba375c17069a1c65c264879993376bb810386c..63e3e7b86af4c2e84971382609709c64a586ce03 100644
--- a/Widgets/AlignMeshesToolbox.hh
+++ b/Widgets/AlignMeshesToolbox.hh
@@ -9,7 +9,7 @@ class AlignMeshesToolbox : public QWidget, public Ui::AlignMeshesToolbox
   Q_OBJECT
 
   public:
-    AlignMeshesToolbox(QWidget *parent = 0);
+    explicit AlignMeshesToolbox(QWidget *parent = 0);
 };
 
 #endif // ALIGN_MESHES_TOOLBOX_HH