diff --git a/src/test/regress/expected/insert_select_connection_leak.out b/src/test/regress/expected/insert_select_connection_leak.out
new file mode 100644
index 000000000..a971c608e
--- /dev/null
+++ b/src/test/regress/expected/insert_select_connection_leak.out
@@ -0,0 +1,103 @@
+CREATE SCHEMA insert_select_connection_leak;
+SET search_path TO 'insert_select_connection_leak';
+SET citus.next_shard_id TO 4213581;
+SET citus.shard_count TO 64;
+CREATE OR REPLACE FUNCTION
+worker_connection_count(nodeport int)
+RETURNS int AS $$
+  SELECT result::int - 1 FROM
+  run_command_on_workers($Q$select count(*) from pg_stat_activity where backend_type = 'client backend';$Q$)
+  WHERE nodeport = nodeport
+$$ LANGUAGE SQL;
+CREATE TABLE source_table(a int, b int);
+SELECT create_distributed_table('source_table', 'a');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+CREATE TABLE target_table(a numeric, b int not null);
+SELECT create_distributed_table('target_table', 'a');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO source_table SELECT i, 2 * i FROM generate_series(1, 10000) i;
+EXPLAIN (costs off) INSERT INTO target_table SELECT * FROM source_table;
+                           QUERY PLAN
+---------------------------------------------------------------------
+ Custom Scan (Citus INSERT ... SELECT)
+   INSERT/SELECT method: repartition
+   ->  Custom Scan (Citus Adaptive)
+         Task Count: 64
+         Tasks Shown: One of 64
+         ->  Task
+               Node: host=localhost port=xxxxx dbname=regression
+               ->  Seq Scan on source_table_4213581 source_table
+(8 rows)
+
+SELECT worker_connection_count(:worker_1_port) AS pre_xact_worker_1_connections,
+       worker_connection_count(:worker_2_port) AS pre_xact_worker_2_connections \gset
+BEGIN;
+INSERT INTO target_table SELECT * FROM source_table;
+SELECT worker_connection_count(:worker_1_port) AS worker_1_connections,
+       worker_connection_count(:worker_2_port) AS worker_2_connections \gset
+INSERT INTO target_table SELECT * FROM source_table;
+INSERT INTO target_table SELECT * FROM source_table;
+INSERT INTO target_table SELECT * FROM source_table;
+INSERT INTO target_table SELECT * FROM source_table;
+SELECT worker_connection_count(:worker_1_port) - :worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :worker_2_connections AS leaked_worker_2_connections;
+ leaked_worker_1_connections | leaked_worker_2_connections
+---------------------------------------------------------------------
+                           0 |                           0
+(1 row)
+
+END;
+SELECT worker_connection_count(:worker_1_port) - :pre_xact_worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :pre_xact_worker_2_connections AS leaked_worker_2_connections;
+ leaked_worker_1_connections | leaked_worker_2_connections
+---------------------------------------------------------------------
+                           0 |                           0
+(1 row)
+
+-- ROLLBACK
+BEGIN;
+INSERT INTO target_table SELECT * FROM source_table;
+INSERT INTO target_table SELECT * FROM source_table;
+ROLLBACK;
+SELECT worker_connection_count(:worker_1_port) - :pre_xact_worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :pre_xact_worker_2_connections AS leaked_worker_2_connections;
+ leaked_worker_1_connections | leaked_worker_2_connections
+---------------------------------------------------------------------
+                           0 |                           0
+(1 row)
+
+\set VERBOSITY TERSE
+-- Error on constraint failure
+BEGIN;
+INSERT INTO target_table SELECT * FROM source_table;
+SELECT worker_connection_count(:worker_1_port) AS worker_1_connections,
+       worker_connection_count(:worker_2_port) AS worker_2_connections \gset
+SAVEPOINT s1;
+INSERT INTO target_table SELECT a, CASE WHEN a < 5000 THEN b ELSE null END  FROM source_table;
+ERROR:  null value in column "b" violates not-null constraint
+ROLLBACK TO SAVEPOINT s1;
+SELECT worker_connection_count(:worker_1_port) - :worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :worker_2_connections AS leaked_worker_2_connections;
+ leaked_worker_1_connections | leaked_worker_2_connections
+---------------------------------------------------------------------
+                           0 |                           0
+(1 row)
+
+END;
+SELECT worker_connection_count(:worker_1_port) - :pre_xact_worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :pre_xact_worker_2_connections AS leaked_worker_2_connections;
+ leaked_worker_1_connections | leaked_worker_2_connections
+---------------------------------------------------------------------
+                           0 |                           0
+(1 row)
+
+SET client_min_messages TO WARNING;
+DROP SCHEMA insert_select_connection_leak CASCADE;
diff --git a/src/test/regress/multi_schedule b/src/test/regress/multi_schedule
index aa5eb2927..1b50e21c5 100644
--- a/src/test/regress/multi_schedule
+++ b/src/test/regress/multi_schedule
@@ -42,10 +42,14 @@ test: multi_read_from_secondaries
 test: multi_create_table
 test: multi_create_table_constraints multi_master_protocol multi_load_data multi_behavioral_analytics_create_table
 test: multi_behavioral_analytics_basics multi_behavioral_analytics_single_shard_queries multi_insert_select_non_pushable_queries multi_insert_select
-test: multi_insert_select_window multi_shard_update_delete window_functions dml_recursive recursive_dml_with_different_planners_executors insert_select_repartition
+test: multi_shard_update_delete recursive_dml_with_different_planners_executors
+test: insert_select_repartition window_functions dml_recursive multi_insert_select_window
 test: multi_insert_select_conflict
 test: multi_row_insert
 
+# following should not run in parallel because it relies on connection counts to workers
+test: insert_select_connection_leak
+
 # ---------
 # at the end of the regression tests regaring recursively planned modifications
 # ensure that we don't leak any intermediate results
diff --git a/src/test/regress/sql/insert_select_connection_leak.sql b/src/test/regress/sql/insert_select_connection_leak.sql
new file mode 100644
index 000000000..167acd9e5
--- /dev/null
+++ b/src/test/regress/sql/insert_select_connection_leak.sql
@@ -0,0 +1,70 @@
+CREATE SCHEMA insert_select_connection_leak;
+SET search_path TO 'insert_select_connection_leak';
+
+SET citus.next_shard_id TO 4213581;
+SET citus.shard_count TO 64;
+
+CREATE OR REPLACE FUNCTION
+worker_connection_count(nodeport int)
+RETURNS int AS $$
+  SELECT result::int - 1 FROM
+  run_command_on_workers($Q$select count(*) from pg_stat_activity where backend_type = 'client backend';$Q$)
+  WHERE nodeport = nodeport
+$$ LANGUAGE SQL;
+
+CREATE TABLE source_table(a int, b int);
+SELECT create_distributed_table('source_table', 'a');
+
+CREATE TABLE target_table(a numeric, b int not null);
+SELECT create_distributed_table('target_table', 'a');
+
+INSERT INTO source_table SELECT i, 2 * i FROM generate_series(1, 10000) i;
+
+EXPLAIN (costs off) INSERT INTO target_table SELECT * FROM source_table;
+
+SELECT worker_connection_count(:worker_1_port) AS pre_xact_worker_1_connections,
+       worker_connection_count(:worker_2_port) AS pre_xact_worker_2_connections \gset
+
+BEGIN;
+INSERT INTO target_table SELECT * FROM source_table;
+SELECT worker_connection_count(:worker_1_port) AS worker_1_connections,
+       worker_connection_count(:worker_2_port) AS worker_2_connections \gset
+INSERT INTO target_table SELECT * FROM source_table;
+INSERT INTO target_table SELECT * FROM source_table;
+INSERT INTO target_table SELECT * FROM source_table;
+INSERT INTO target_table SELECT * FROM source_table;
+SELECT worker_connection_count(:worker_1_port) - :worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :worker_2_connections AS leaked_worker_2_connections;
+END;
+
+SELECT worker_connection_count(:worker_1_port) - :pre_xact_worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :pre_xact_worker_2_connections AS leaked_worker_2_connections;
+
+-- ROLLBACK
+BEGIN;
+INSERT INTO target_table SELECT * FROM source_table;
+INSERT INTO target_table SELECT * FROM source_table;
+ROLLBACK;
+
+SELECT worker_connection_count(:worker_1_port) - :pre_xact_worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :pre_xact_worker_2_connections AS leaked_worker_2_connections;
+
+\set VERBOSITY TERSE
+
+-- Error on constraint failure
+BEGIN;
+INSERT INTO target_table SELECT * FROM source_table;
+SELECT worker_connection_count(:worker_1_port) AS worker_1_connections,
+       worker_connection_count(:worker_2_port) AS worker_2_connections \gset
+SAVEPOINT s1;
+INSERT INTO target_table SELECT a, CASE WHEN a < 5000 THEN b ELSE null END  FROM source_table;
+ROLLBACK TO SAVEPOINT s1;
+SELECT worker_connection_count(:worker_1_port) - :worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :worker_2_connections AS leaked_worker_2_connections;
+END;
+
+SELECT worker_connection_count(:worker_1_port) - :pre_xact_worker_1_connections AS leaked_worker_1_connections,
+       worker_connection_count(:worker_2_port) - :pre_xact_worker_2_connections AS leaked_worker_2_connections;
+
+SET client_min_messages TO WARNING;
+DROP SCHEMA insert_select_connection_leak CASCADE;