diff --git a/doc/container.qbk b/doc/container.qbk
index 308b296..76a0fdf 100644
--- a/doc/container.qbk
+++ b/doc/container.qbk
@@ -1320,6 +1320,7 @@ use [*Boost.Container]? There are several reasons for that:
 [section:release_notes_boost_1_74_00 Boost 1.74 Release]
 
 * Fixed bugs/issues:
+   * [@https://github.com/boostorg/container/issues/126    GitHub #126: ['"flat_set.hpp and set.hpp in pmr have the same header guard"]].
    * [@https://github.com/boostorg/container/issues/129    GitHub #129: ['"Alias templates for small_flat_[multi]{set|map} using small_vector as container"]].
    * [@https://github.com/boostorg/container/pull/135      GitHub #135: ['"Missing BOOST_NORETURN for user defined functions"]].
    * [@https://github.com/boostorg/container/pull/137      GitHub #137: ['"RandomAccessIterator + 0"]].
diff --git a/include/boost/container/pmr/flat_set.hpp b/include/boost/container/pmr/flat_set.hpp
index f072c95..c9e26b7 100644
--- a/include/boost/container/pmr/flat_set.hpp
+++ b/include/boost/container/pmr/flat_set.hpp
@@ -8,8 +8,8 @@
 //
 //////////////////////////////////////////////////////////////////////////////
 
-#ifndef BOOST_CONTAINER_PMR_SET_HPP
-#define BOOST_CONTAINER_PMR_SET_HPP
+#ifndef BOOST_CONTAINER_PMR_FLAT_SET_HPP
+#define BOOST_CONTAINER_PMR_FLAT_SET_HPP
 
 #if defined (_MSC_VER)
 #  pragma once 
@@ -56,4 +56,4 @@ struct flat_multiset_of
 }  //namespace container {
 }  //namespace boost {
 
-#endif   //BOOST_CONTAINER_PMR_SET_HPP
+#endif   //BOOST_CONTAINER_PMR_FLAT_SET_HPP