diff --git a/Reference/Visitor.h b/Reference/Visitor.h
index 2b29f0e..a52fcbe 100644
--- a/Reference/Visitor.h
+++ b/Reference/Visitor.h
@@ -158,7 +158,7 @@ struct DefaultCatchAll
 ////////////////////////////////////////////////////////////////////////////////
 
 #define DEFINE_VISITABLE() \
-    virtual ReturnType Accept(BaseVisitor& guest) \
+    virtual ReturnType Accept(Loki::BaseVisitor& guest) \
     { return AcceptImpl(*this, guest); }
 
 ////////////////////////////////////////////////////////////////////////////////