diff --git a/tests/bugs/gh_7137_test.py b/tests/bugs/gh_7137_test.py
new file mode 100644
index 00000000..9d5747dd
--- /dev/null
+++ b/tests/bugs/gh_7137_test.py
@@ -0,0 +1,110 @@
+#coding:utf-8
+
+"""
+ID:          issue-7137
+ISSUE:       https://github.com/FirebirdSQL/firebird/issues/7137
+TITLE:       Optimizer regression: bad plan (HASH instead of JOIN) is chosen for some inner joins
+NOTES:
+    [26.04.2022] pzotov
+    Confirmed bug (ineffective execution plan) on 3.0.9.33560 (09.02.2022).
+    Checked on 6.0.0.336, 5.0.1.1383, 4.0.5.3086, 3.0.10.33569 (24.02.2022) - all fine.
+"""
+
+import pytest
+from firebird.qa import *
+
+init_sql = """
+    recreate table test_c(x int);
+    commit;
+
+    recreate table test_a(
+        id int unique using index test_a_pk
+        ,ico int
+        ,name varchar(50)
+    );
+    create index test_a_name on test_a(name);
+
+    recreate table test_b(
+        id int primary key using index test_b_pk
+       ,ico int
+       ,name varchar(50)
+    );
+
+
+    recreate table test_c(
+        id int primary key using index test_c_pk
+       ,pid_a int references test_a(id) using index test_c_fk
+    );
+
+    insert into test_a(id, ico, name)
+    select row_number()over(), mod( row_number()over(), 10 ), ascii_char(64 + mod( row_number()over(), 10 ))
+    from rdb$types
+    rows 200;
+
+    insert into test_b(id, ico, name)
+    select row_number()over()-1, mod( row_number()over(), 10 ), ascii_char(64 + mod( row_number()over(), 10 ))
+    from rdb$types, rdb$types
+    rows 10000;
+
+    insert into test_c(id, pid_a)
+    select row_number()over(), 1 + mod( row_number()over(), 100 )
+    from rdb$types, rdb$types
+    rows 10000;
+    commit;
+
+    set statistics index test_a_pk;
+    set statistics index test_a_name;
+    set statistics index test_b_pk;
+    set statistics index test_c_pk;
+    set statistics index test_c_fk;
+    commit;
+"""
+
+db = db_factory(init = init_sql)
+
+query_lst = [
+    """
+        select 1
+        from test_a a
+        join test_b b on b.ico = a.ico
+        join test_c c on c.pid_a = a.id
+        where b.id = 0 and a.name = b.name
+    """,
+]
+
+act = python_act('db')
+
+#---------------------------------------------------------
+def replace_leading(source, char="."):
+    stripped = source.lstrip()
+    return char * (len(source) - len(stripped)) + stripped
+#---------------------------------------------------------
+
+@pytest.mark.version('>=3.0.9')
+def test_1(act: Action, capsys):
+    with act.db.connect() as con:
+        cur = con.cursor()
+        for q in query_lst:
+            with cur.prepare(q) as ps:
+                print( '\n'.join([replace_leading(s) for s in ps.detailed_plan .split('\n')]) )
+
+    expected_stdout = """
+        Select Expression
+        ....-> Nested Loop Join (inner)
+        ........-> Filter
+        ............-> Table "TEST_B" as "B" Access By ID
+        ................-> Bitmap
+        ....................-> Index "TEST_B_PK" Unique Scan
+        ........-> Filter
+        ............-> Table "TEST_A" as "A" Access By ID
+        ................-> Bitmap
+        ....................-> Index "TEST_A_NAME" Range Scan (full match)
+        ........-> Filter
+        ............-> Table "TEST_C" as "C" Access By ID
+        ................-> Bitmap
+        ....................-> Index "TEST_C_FK" Range Scan (full match)
+    """
+   
+    act.expected_stdout = expected_stdout
+    act.stdout = capsys.readouterr().out
+    assert act.clean_stdout == act.clean_expected_stdout