diff --git a/include/boost/ratio/detail/overflow_helpers.hpp b/include/boost/ratio/detail/overflow_helpers.hpp
index 5eb4d25..59595c6 100644
--- a/include/boost/ratio/detail/overflow_helpers.hpp
+++ b/include/boost/ratio/detail/overflow_helpers.hpp
@@ -242,8 +242,8 @@ namespace ratio_detail
              >
          >::type type;
   };
-  template <class R>
-  struct ratio_add<R, ratio<0> >
+  template <class R, boost::intmax_t D>
+  struct ratio_add<R, ratio<0,D> >
   {
     typedef R type;
   };
@@ -274,8 +274,8 @@ namespace ratio_detail
          >::type type;
   };
   
-  template <class R>
-  struct ratio_subtract<R, ratio<0> >
+  template <class R, boost::intmax_t D>
+  struct ratio_subtract<R, ratio<0,D> >
   {
     typedef R type;
   };
diff --git a/include/boost/ratio/ratio_io.hpp b/include/boost/ratio/ratio_io.hpp
index 90b0e6a..1b87788 100644
--- a/include/boost/ratio/ratio_io.hpp
+++ b/include/boost/ratio/ratio_io.hpp
@@ -418,9 +418,9 @@ template <>
 struct ratio_string<milli, char16_t>
 {
     static std::u16string short_name() {return std::u16string(1, u'm');}
-    static std::u32string long_name()  {return std::u16string(u"milli");}
-    static std::u32string symbol() {return short_name();}
-    static std::u32string prefix() {return long_name();}
+    static std::u16string long_name()  {return std::u16string(u"milli");}
+    static std::u16string symbol() {return short_name();}
+    static std::u16string prefix() {return long_name();}
 };
 
 template <>