diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 81426dc2a89..2e1f141bac8 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2013-03-22  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR libstdc++/56678
+	* include/std/chrono (__is_ratio): Uglify T.
+
 2013-03-18  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR libstdc++/55977 (partial, std::vector and std::deque bits)
diff --git a/libstdc++-v3/include/std/chrono b/libstdc++-v3/include/std/chrono
index e4b92a59405..711131920f0 100644
--- a/libstdc++-v3/include/std/chrono
+++ b/libstdc++-v3/include/std/chrono
@@ -225,7 +225,7 @@ _GLIBCXX_END_NAMESPACE_VERSION
 	{ return numeric_limits<_Rep>::lowest(); }
       };
 
-    template<typename T>
+    template<typename _Tp>
       struct __is_ratio
       : std::false_type
       { };