diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 2474a69e805..7beb037110d 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,7 @@
+2019-10-03  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
+
+	* include/parallel/multiway_merge.h (_RAIter3): Replace _C by _Cp.
+
 2019-10-02  Jonathan Wakely  <jwakely@redhat.com>
 
 	* config/abi/pre/gnu.ver: Tighten up greedy wildcards.
diff --git a/libstdc++-v3/include/parallel/multiway_merge.h b/libstdc++-v3/include/parallel/multiway_merge.h
index c5f85881ace..63ad27403c6 100644
--- a/libstdc++-v3/include/parallel/multiway_merge.h
+++ b/libstdc++-v3/include/parallel/multiway_merge.h
@@ -232,7 +232,7 @@ namespace __gnu_parallel
    *
    * @return End iterator of output sequence.
    */
-  template<template<typename _RAI, typename _C> class iterator,
+  template<template<typename _RAI, typename _Cp> class iterator,
            typename _RAIterIterator,
            typename _RAIter3,
            typename _DifferenceTp,
@@ -351,7 +351,7 @@ namespace __gnu_parallel
    *
    * @return End iterator of output sequence.
    */
-  template<template<typename _RAI, typename _C> class iterator,
+  template<template<typename _RAI, typename _Cp> class iterator,
            typename _RAIterIterator,
            typename _RAIter3,
            typename _DifferenceTp,