diff --git a/include/vsg/io/Output.h b/include/vsg/io/Output.h
index cc547e4d5..523a2cc8c 100644
--- a/include/vsg/io/Output.h
+++ b/include/vsg/io/Output.h
@@ -177,7 +177,7 @@ namespace vsg
 
         /// match propertyname and write value(s)
         template<typename... Args>
-        void write(const char* propertyName, Args&... args)
+        void write(const char* propertyName, const Args&... args)
         {
             writePropertyName(propertyName);