diff --git a/tests/dbshell/test_mysql.py b/tests/dbshell/test_mysql.py
index b002a5d274..c3ecc6503b 100644
--- a/tests/dbshell/test_mysql.py
+++ b/tests/dbshell/test_mysql.py
@@ -1,3 +1,4 @@
+import os
 import subprocess
 import sys
 from pathlib import Path
@@ -190,6 +191,8 @@ class MySqlDbshellCommandTestCase(SimpleTestCase):
             },
             [],
         )
+        if env:
+            env = {**os.environ, **env}
         fake_client = Path(__file__).with_name('fake_client.py')
         args[0:1] = [sys.executable, str(fake_client)]
         with self.assertRaises(subprocess.CalledProcessError) as ctx:
diff --git a/tests/dbshell/test_postgresql.py b/tests/dbshell/test_postgresql.py
index 4d8804e43e..ccf49d7e50 100644
--- a/tests/dbshell/test_postgresql.py
+++ b/tests/dbshell/test_postgresql.py
@@ -1,3 +1,4 @@
+import os
 import signal
 import subprocess
 import sys
@@ -121,6 +122,8 @@ class PostgreSqlDbshellCommandTestCase(SimpleTestCase):
         # The password doesn't leak in an exception that results from a client
         # crash.
         args, env = self.settings_to_cmd_args_env({'PASSWORD': 'somepassword'}, [])
+        if env:
+            env = {**os.environ, **env}
         fake_client = Path(__file__).with_name('fake_client.py')
         args[0:1] = [sys.executable, str(fake_client)]
         with self.assertRaises(subprocess.CalledProcessError) as ctx: