diff --git a/plugins/autotest/testtreeitem.cpp b/plugins/autotest/testtreeitem.cpp
index 4dc78f3aa15..6c29f886e85 100644
--- a/plugins/autotest/testtreeitem.cpp
+++ b/plugins/autotest/testtreeitem.cpp
@@ -73,7 +73,7 @@ static QIcon testTreeIcon(TestTreeItem::Type type)
         QIcon(QLatin1String(":/images/func.png")),
         QIcon(QLatin1String(":/images/data.png"))
     };
-    if (static_cast<unsigned long>(type) >= sizeof(icons))
+    if (int(type) >= int(sizeof icons / sizeof *icons))
         return icons[2];
     return icons[type];
 }