diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2b01b99b..302573c7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@ Version 65:
 * Enable narrowing warning on msvc cmake
 * Fix integer types in deflate_stream::bi_reverse
 * Fix narrowing in static_ostream
+* Fix narrowing in ostream
 
 --------------------------------------------------------------------------------
 
diff --git a/include/beast/core/detail/ostream.hpp b/include/beast/core/detail/ostream.hpp
index 1fafffe7..c0221124 100644
--- a/include/beast/core/detail/ostream.hpp
+++ b/include/beast/core/detail/ostream.hpp
@@ -105,7 +105,8 @@ public:
     {
         if(! Traits::eq_int_type(ch, Traits::eof()))
         {
-            Traits::assign(*this->pptr(), ch);
+            Traits::assign(*this->pptr(),
+                static_cast<CharT>(ch));
             flush(1);
             prepare();
             return ch;
@@ -185,7 +186,8 @@ public:
     {
         if(! Traits::eq_int_type(ch, Traits::eof()))
         {
-            Traits::assign(*this->pptr(), ch);
+            Traits::assign(*this->pptr(),
+                static_cast<CharT>(ch));
             flush(1);
             prepare();
             return ch;