diff --git a/types/tagged.hpp b/types/tagged.hpp
index 42d7c2d3..fdc8a51b 100644
--- a/types/tagged.hpp
+++ b/types/tagged.hpp
@@ -81,8 +81,8 @@ namespace cruft {
 
         ///--------------------------------------------------------------------
         /// Return the type code associated with the stored value.
-        auto tag (void) const { return m_tag; }
-        auto tag (void)       { return m_tag; }
+        tag_t tag (void) const { return m_tag; }
+        tag_t tag (void)       { return m_tag; }
 
 
         /// Returns true if the contained type is the same as the type