diff --git a/c_src/quicer_config.c b/c_src/quicer_config.c
index 33df9714..565c73e8 100644
--- a/c_src/quicer_config.c
+++ b/c_src/quicer_config.c
@@ -760,6 +760,10 @@ encode_parm_to_eterm(ErlNifEnv *env,
                && QUICER_PARAM_HANDLE_TYPE_CONN == Type))
     {
       ERL_NIF_TERM ebin;
+      if (QUIC_PARAM_CONN_CLOSE_REASON_PHRASE == Param)
+        {
+          BufferLength -= 1; // remove \0
+        }
       unsigned char *bin_data = enif_make_new_binary(env, BufferLength, &ebin);
       if (!bin_data)
         {
diff --git a/test/quicer_SUITE.erl b/test/quicer_SUITE.erl
index 0cc5af7a..a11e45c9 100644
--- a/test/quicer_SUITE.erl
+++ b/test/quicer_SUITE.erl
@@ -965,8 +965,9 @@ tc_getopt(Config) ->
                 {quic, <<"ping">>, Stm, _} -> ok
             end,
             ok = quicer:close_connection(Conn),
-            %% @todo unsupp in msquic, leave it for now
-            {error, _} = quicer:getopt(Conn, close_reason_phrase),
+            %% @NOTE: msquic returns not_found when it is unset.
+            {error, Reason} = quicer:getopt(Conn, close_reason_phrase),
+            ?assert(Reason == not_found orelse Reason == closed),
             SPid ! done,
             ensure_server_exit_normal(Ref)
     after 5000 ->
@@ -1370,7 +1371,8 @@ tc_setopt(Config) ->
 
             {error, not_supported} = quicer:setopt(Conn, ideal_processor, 1),
             {error, not_supported} = quicer:setopt(Conn, max_stream_ids, [1, 2, 3, 4]),
-            ok = quicer:setopt(Conn, close_reason_phrase, "You are not welcome!"),
+            ok = quicer:setopt(Conn, close_reason_phrase, "You are not welcomed!"),
+            {ok, <<"You are not welcomed!">>} = quicer:getopt(Conn, close_reason_phrase),
             ok = quicer:setopt(Conn, stream_scheduling_scheme, 1),
             {ok, 1} = quicer:getopt(Conn, stream_scheduling_scheme),
             %% get-only