diff --git a/CHANGELOG.md b/CHANGELOG.md
index d4b3eafa..78a70ef5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,10 @@
+Version 231:
+
+* Doc section names are stable
+* Add missing include
+
+--------------------------------------------------------------------------------
+
 Version 230:
 
 * Don't use dynamic_buffer_ref
diff --git a/include/boost/beast/_experimental/unit_test/dstream.hpp b/include/boost/beast/_experimental/unit_test/dstream.hpp
index 7f920ab7..60066ac7 100644
--- a/include/boost/beast/_experimental/unit_test/dstream.hpp
+++ b/include/boost/beast/_experimental/unit_test/dstream.hpp
@@ -14,6 +14,7 @@
 #include <ios>
 #include <memory>
 #include <ostream>
+#include <sstream>
 #include <streambuf>
 #include <string>