diff --git a/include/cantera/base/Units.h b/include/cantera/base/Units.h
index 2591d487547..5521de07361 100644
--- a/include/cantera/base/Units.h
+++ b/include/cantera/base/Units.h
@@ -35,7 +35,7 @@ class Units
                    double quantity=0);
 
     //! Create an object with the specified dimensions
-    explicit Units(const std::string& name);
+    Units(const std::string& name);
 
     //! Returns `true` if the specified Units are dimensionally consistent
     bool convertible(const Units& other) const;