diff --git a/tests/bugs/gh_8386_test.py b/tests/bugs/gh_8386_test.py
new file mode 100644
index 00000000..65417da0
--- /dev/null
+++ b/tests/bugs/gh_8386_test.py
@@ -0,0 +1,119 @@
+#coding:utf-8
+
+"""
+ID:          issue-8386
+ISSUE:       https://github.com/FirebirdSQL/firebird/issues/8386
+TITLE:       Crash when creating index on table that uses UDR and ParallelWorkers > 1
+DESCRIPTION: 
+NOTES:
+    [17.01.2025] pzotov
+    Currenty fix presents only in 5.x (commit 4ddbb69). Because of that, 6.x not checked (but it is also affected).
+
+    Confirmed bug on 5.0.2.1589, got: "SQLSTATE = 08006 / Error reading data from the connection".
+    Checked on 5.0.2.1592 -- all fine.
+    WAITING FOR FRONT-PORT FIX INTO FB 6.X.
+"""
+
+import pytest
+from firebird.qa import *
+
+db = db_factory()
+
+test_script = """
+    set bail on;
+    set list on;
+    create exception exc_parallel_workers_required q'[Config parameter ParallelWorkers = @1 must be set to 2 or greater.]';
+    create exception exc_udr_func_seems_not_working q'[UDR function 'sum_args' either not defined or is invalid]';
+    create exception exc_not_enough_data_for_test q'[At least 2 PP must be allocated for data of 'TEST' table. Currently only @1 PP are used.]';
+
+    -- create UDR
+    create function sum_args (
+        n1 integer,
+        n2 integer,
+        n3 integer
+    ) returns integer
+        external name 'udrcpp_example!sum_args'
+        engine udr
+    ;
+
+    set term ^;
+    execute block as
+        declare n int;
+    begin
+        select rdb$config_value from rdb$config where rdb$config_name = 'ParallelWorkers' into n;
+        if (n is null or n <= 1) then
+            exception exc_parallel_workers_required using (n);
+        --------------------------------------------
+        select sum_args(1, 2, 3) from rdb$database into n;
+        if (n is distinct from 6) then
+            exception exc_udr_func_seems_not_working;
+
+    end
+    ^
+    set term ;^
+    commit;
+
+    -- create table with dependency on UDR
+    create table test (
+        f1 int,
+        f2 int,
+        f3 int,
+        f_sum computed by (sum_args(f1, f2, f3))
+    );
+
+    -- fill it with some data
+    insert into test values (1, 1, 1);
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    insert into test select f1, f2, f3 from test;
+    commit;
+
+    set term ^;
+    execute block as
+        declare n int;
+    begin
+        -- make sure there are at least 2 pointer pages
+        select count(*) from rdb$pages p join rdb$relations r on p.rdb$relation_id = r.rdb$relation_id
+        where r.rdb$relation_name = upper('test') and p.rdb$page_type = 4
+        into n;
+        if (n < 2) then
+            exception exc_not_enough_data_for_test using (n);
+
+    end
+    ^
+    set term ;^
+    commit;
+
+    -- create index 
+    create index test_idx_f1 on test(f1);
+
+    -- THIS MUST BE DISPLAYED. CRASH WAS HERE BEFORE FIX:
+    select 'Completed' as msg from rdb$database;
+"""
+
+act = isql_act('db', test_script, substitutions = [('[ \t]+', ' ')])
+
+@pytest.mark.version('>=5.0.2,<6')
+def test_1(act: Action):
+    if act.vars['server-arch'] != 'SuperServer':
+        pytest.skip("Only SuperServer affected")
+
+    act.expected_stdout = 'MSG Completed'
+    act.execute(combine_output = True)
+    assert act.clean_stdout == act.clean_expected_stdout
+