diff --git a/CHANGELOG.md b/CHANGELOG.md
index d785dc2a9..2370d20e2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Fixed
+
+- 🐛(backend) close thread DB connections to fix test teardown 
+  OperationalError #2385
+
 ## [v5.2.0] - 2026-06-03
 
 ### Added
diff --git a/src/backend/core/tests/documents/test_api_documents_children_create.py b/src/backend/core/tests/documents/test_api_documents_children_create.py
index 355e9236c..d5e25f7bb 100644
--- a/src/backend/core/tests/documents/test_api_documents_children_create.py
+++ b/src/backend/core/tests/documents/test_api_documents_children_create.py
@@ -8,6 +8,8 @@ from unittest import mock
 from unittest.mock import patch
 from uuid import uuid4
 
+from django.db import connection
+
 import pytest
 from rest_framework.test import APIClient
 
@@ -286,12 +288,17 @@ def test_api_documents_create_document_children_race_condition():
     factories.UserDocumentAccessFactory(user=user, document=document, role="owner")
 
     def create_document():
-        return client.post(
-            f"/api/v1.0/documents/{document.id}/children/",
-            {
-                "title": "my child",
-            },
-        )
+        try:
+            return client.post(
+                f"/api/v1.0/documents/{document.id}/children/",
+                {
+                    "title": "my child",
+                },
+            )
+        finally:
+            # Close this worker thread's thread-local database connection so it
+            # does not linger and block dropping the test database at teardown.
+            connection.close()
 
     with ThreadPoolExecutor(max_workers=2) as executor:
         future1 = executor.submit(create_document)
diff --git a/src/backend/core/tests/documents/test_api_documents_create.py b/src/backend/core/tests/documents/test_api_documents_create.py
index c2896e2aa..46d34ccf7 100644
--- a/src/backend/core/tests/documents/test_api_documents_create.py
+++ b/src/backend/core/tests/documents/test_api_documents_create.py
@@ -6,6 +6,8 @@ from concurrent.futures import ThreadPoolExecutor
 from unittest import mock
 from uuid import uuid4
 
+from django.db import connection
+
 import pytest
 from rest_framework.test import APIClient
 
@@ -70,16 +72,21 @@ def test_api_documents_create_document_race_condition():
     """
 
     def create_document(title):
-        user = factories.UserFactory()
-        client = APIClient()
-        client.force_login(user)
-        return client.post(
-            "/api/v1.0/documents/",
-            {
-                "title": title,
-            },
-            format="json",
-        )
+        try:
+            user = factories.UserFactory()
+            client = APIClient()
+            client.force_login(user)
+            return client.post(
+                "/api/v1.0/documents/",
+                {
+                    "title": title,
+                },
+                format="json",
+            )
+        finally:
+            # Close this worker thread's thread-local database connection so it
+            # does not linger and block dropping the test database at teardown.
+            connection.close()
 
     with ThreadPoolExecutor(max_workers=2) as executor:
         future1 = executor.submit(create_document, "my document 1")
diff --git a/src/backend/core/tests/documents/test_api_documents_create_for_owner.py b/src/backend/core/tests/documents/test_api_documents_create_for_owner.py
index cf02674c2..7c15e7f1a 100644
--- a/src/backend/core/tests/documents/test_api_documents_create_for_owner.py
+++ b/src/backend/core/tests/documents/test_api_documents_create_for_owner.py
@@ -9,6 +9,7 @@ from unittest import mock
 from unittest.mock import patch
 
 from django.core import mail
+from django.db import connection
 from django.test import override_settings
 
 import pytest
@@ -480,16 +481,21 @@ def test_api_documents_create_document_race_condition():
     """
 
     def create_document(title):
-        user = factories.UserFactory()
-        client = APIClient()
-        client.force_login(user)
-        return client.post(
-            "/api/v1.0/documents/",
-            {
-                "title": title,
-            },
-            format="json",
-        )
+        try:
+            user = factories.UserFactory()
+            client = APIClient()
+            client.force_login(user)
+            return client.post(
+                "/api/v1.0/documents/",
+                {
+                    "title": title,
+                },
+                format="json",
+            )
+        finally:
+            # Close this worker thread's thread-local database connection so it
+            # does not linger and block dropping the test database at teardown.
+            connection.close()
 
     with ThreadPoolExecutor(max_workers=2) as executor:
         future1 = executor.submit(create_document, "my document 1")
diff --git a/src/backend/core/tests/test_models_users.py b/src/backend/core/tests/test_models_users.py
index f1b044db4..b8bc20ffc 100644
--- a/src/backend/core/tests/test_models_users.py
+++ b/src/backend/core/tests/test_models_users.py
@@ -7,6 +7,7 @@ from concurrent.futures import ThreadPoolExecutor
 from unittest.mock import patch
 
 from django.core.exceptions import ValidationError
+from django.db import connection
 from django.test.utils import override_settings
 
 import pytest
@@ -341,7 +342,14 @@ def test_models_users_duplicate_onboarding_sandbox_race_condition():
     """
 
     def create_user():
-        return factories.UserFactory()
+        try:
+            return factories.UserFactory()
+        finally:
+            # Each worker thread gets its own thread-local database connection.
+            # Close it explicitly so it does not linger and block dropping the
+            # test database during teardown (OperationalError: "database is being
+            # accessed by other users").
+            connection.close()
 
     template_document = factories.DocumentFactory(title="Getting started with Docs")
     with (