diff --git a/big_tests/tests/graphql_sse_SUITE.erl b/big_tests/tests/graphql_sse_SUITE.erl
index 8a7a097c3ea..6937e45f0cf 100644
--- a/big_tests/tests/graphql_sse_SUITE.erl
+++ b/big_tests/tests/graphql_sse_SUITE.erl
@@ -21,7 +21,7 @@ all() ->
 groups() ->
     [{admin, [parallel], admin_tests()},
      {user, [parallel], user_tests()},
-     {timeout, [], [sse_should_not_get_timeout]}].
+     {timeout, [parallel], [sse_should_not_get_timeout, sse_works_with_long_messages]}].
 
 init_per_suite(Config) ->
     Config1 = escalus:init_per_suite(Config),
@@ -148,6 +148,17 @@ sse_should_not_get_timeout(Config) ->
         sse_helper:stop_sse(Stream)
     end).
 
+sse_works_with_long_messages(Config) ->
+    escalus:fresh_story(Config, [{alice, 1}, {bob, 1}], fun (Alice, Bob) ->
+        From = escalus_client:full_jid(Bob),
+        To = escalus_client:short_jid(Alice),
+        {200, Stream} = graphql_helper:execute_user_command_sse(<<"stanza">>, <<"subscribeForMessages">>, Alice, #{}, Config),
+        Message = binary:copy(<<"0">>, 2000),
+        escalus:send(Bob, escalus_stanza:chat(From, To, Message)),
+        sse_helper:wait_for_event(Stream),
+        sse_helper:stop_sse(Stream)
+    end).
+
 %% Helpers
 
 get_graphql_user_listener() ->
diff --git a/src/graphql/mongoose_graphql_response.erl b/src/graphql/mongoose_graphql_response.erl
index f8a44fec83b..64d5602393b 100644
--- a/src/graphql/mongoose_graphql_response.erl
+++ b/src/graphql/mongoose_graphql_response.erl
@@ -3,10 +3,10 @@
 -export([term_to_json/1, term_to_pretty_json/1]).
 
 term_to_json(Term) ->
-    jiffy:encode(fixup(Term)).
+    iolist_to_binary(jiffy:encode(fixup(Term))).
 
 term_to_pretty_json(Term) ->
-    jiffy:encode(fixup(Term), [pretty]).
+    iolist_to_binary(jiffy:encode(fixup(Term), [pretty])).
 
 %% Ground types
 fixup(Term) when is_number(Term) -> Term;