diff --git a/doc/interprocess.qbk b/doc/interprocess.qbk
index 05e8766..ea25a1e 100644
--- a/doc/interprocess.qbk
+++ b/doc/interprocess.qbk
@@ -6762,6 +6762,12 @@ thank them:
 
 [section:release_notes Release Notes]
 
+[section:release_notes_boost_1_66_00 Boost 1.66 Release]
+*  Fixed bugs:
+   * [@https://github.com/boostorg/interprocess/pull/41 GitHub Pull #41 (['"Data race in boost::interprocess::rbtree_best_fit"])].
+
+[endsect]
+
 [section:release_notes_boost_1_65_00 Boost 1.65 Release]
 *  Fixed bugs:
    * [@https://github.com/boostorg/interprocess/pull/37 GitHub Pull #37 (['"Conditionally replace deprecated/removed std::auto_ptr..."])].
diff --git a/include/boost/interprocess/mem_algo/rbtree_best_fit.hpp b/include/boost/interprocess/mem_algo/rbtree_best_fit.hpp
index dc4307f..7ad9d74 100644
--- a/include/boost/interprocess/mem_algo/rbtree_best_fit.hpp
+++ b/include/boost/interprocess/mem_algo/rbtree_best_fit.hpp
@@ -109,7 +109,7 @@ class rbtree_best_fit
    {
       //!This block's memory size (including block_ctrl
       //!header) in Alignment units
-      size_type m_prev_size :  sizeof(size_type)*CHAR_BIT;
+      size_type m_prev_size;
       size_type m_size      :  sizeof(size_type)*CHAR_BIT - 2;
       size_type m_prev_allocated :  1;
       size_type m_allocated :  1;