diff --git a/plugins/clang/codecompletion/model.cpp b/plugins/clang/codecompletion/model.cpp
--- a/plugins/clang/codecompletion/model.cpp
+++ b/plugins/clang/codecompletion/model.cpp
@@ -199,6 +199,10 @@
     if (userInsertion && lastChar == QLatin1Char('-') && includePathCompletionRequired(view->document()->line(position.line()))) {
         return true;
     }
+    if (userInsertion && inserted.endsWith(QStringLiteral("::"))) {
+        return true;
+    }
+
     return KDevelop::CodeCompletionModel::shouldStartCompletion(view, inserted, userInsertion, position);
 }