diff --git a/test/asynchronous/test_encryption.py b/test/asynchronous/test_encryption.py
index 3b9096ef6a..f9b03f6303 100644
--- a/test/asynchronous/test_encryption.py
+++ b/test/asynchronous/test_encryption.py
@@ -2692,7 +2692,7 @@ async def test_8_csfle_joins_qe(self):
                     ]
                 )
             )
-            self.assertTrue("not supported" in str(exc))
+            self.assertIn("not supported", str(exc))
 
     @async_client_context.require_version_max(8, 1, -1)
     async def test_9_error(self):
@@ -2721,7 +2721,7 @@ async def test_9_error(self):
                     ]
                 )
             )
-            self.assertTrue("Upgrade" in str(exc))
+            self.assertIn("Upgrade", str(exc))
 
 
 # https://github.com/mongodb/specifications/blob/072601/source/client-side-encryption/tests/README.md#rewrap
diff --git a/test/asynchronous/test_pooling.py b/test/asynchronous/test_pooling.py
index 81ed16f2d5..64c5738dba 100644
--- a/test/asynchronous/test_pooling.py
+++ b/test/asynchronous/test_pooling.py
@@ -450,7 +450,7 @@ async def test_csot_timeout_message(self):
                 with timeout(0.5):
                     await client.db.t.find_one({"$where": delay(2)})
 
-        self.assertTrue("(configured timeouts: timeoutMS: 500.0ms" in str(error.exception))
+        self.assertIn("(configured timeouts: timeoutMS: 500.0ms", str(error.exception))
 
     @async_client_context.require_failCommand_appName
     async def test_socket_timeout_message(self):
@@ -475,9 +475,9 @@ async def test_socket_timeout_message(self):
             with self.assertRaises(Exception) as error:
                 await client.db.t.find_one({"$where": delay(2)})
 
-        self.assertTrue(
-            "(configured timeouts: socketTimeoutMS: 500.0ms, connectTimeoutMS: 20000.0ms)"
-            in str(error.exception)
+        self.assertIn(
+            "(configured timeouts: socketTimeoutMS: 500.0ms, connectTimeoutMS: 20000.0ms)",
+            str(error.exception),
         )
 
     @async_client_context.require_failCommand_appName
@@ -507,9 +507,9 @@ async def test_connection_timeout_message(self):
             with self.assertRaises(Exception) as error:
                 await client.admin.command("ping")
 
-        self.assertTrue(
-            "(configured timeouts: socketTimeoutMS: 500.0ms, connectTimeoutMS: 500.0ms)"
-            in str(error.exception)
+        self.assertIn(
+            "(configured timeouts: socketTimeoutMS: 500.0ms, connectTimeoutMS: 500.0ms)",
+            str(error.exception),
         )
 
 
diff --git a/test/test_bson.py b/test/test_bson.py
index 6f26856b00..1616c513c2 100644
--- a/test/test_bson.py
+++ b/test/test_bson.py
@@ -558,7 +558,7 @@ def test_unknown_type(self):
                 decode(bs)
             except Exception as exc:
                 self.assertTrue(isinstance(exc, InvalidBSON))
-                self.assertTrue(part in str(exc))
+                self.assertIn(part, str(exc))
             else:
                 self.fail("Failed to raise an exception.")
 
diff --git a/test/test_encryption.py b/test/test_encryption.py
index 6d669a538d..5bbf8c8ad8 100644
--- a/test/test_encryption.py
+++ b/test/test_encryption.py
@@ -2676,7 +2676,7 @@ def test_8_csfle_joins_qe(self):
                     ]
                 )
             )
-            self.assertTrue("not supported" in str(exc))
+            self.assertIn("not supported", str(exc))
 
     @client_context.require_version_max(8, 1, -1)
     def test_9_error(self):
@@ -2705,7 +2705,7 @@ def test_9_error(self):
                     ]
                 )
             )
-            self.assertTrue("Upgrade" in str(exc))
+            self.assertIn("Upgrade", str(exc))
 
 
 # https://github.com/mongodb/specifications/blob/072601/source/client-side-encryption/tests/README.md#rewrap
diff --git a/test/test_pooling.py b/test/test_pooling.py
index 44e8c4afe5..05513afe12 100644
--- a/test/test_pooling.py
+++ b/test/test_pooling.py
@@ -450,7 +450,7 @@ def test_csot_timeout_message(self):
                 with timeout(0.5):
                     client.db.t.find_one({"$where": delay(2)})
 
-        self.assertTrue("(configured timeouts: timeoutMS: 500.0ms" in str(error.exception))
+        self.assertIn("(configured timeouts: timeoutMS: 500.0ms", str(error.exception))
 
     @client_context.require_failCommand_appName
     def test_socket_timeout_message(self):
@@ -473,9 +473,9 @@ def test_socket_timeout_message(self):
             with self.assertRaises(Exception) as error:
                 client.db.t.find_one({"$where": delay(2)})
 
-        self.assertTrue(
-            "(configured timeouts: socketTimeoutMS: 500.0ms, connectTimeoutMS: 20000.0ms)"
-            in str(error.exception)
+        self.assertIn(
+            "(configured timeouts: socketTimeoutMS: 500.0ms, connectTimeoutMS: 20000.0ms)",
+            str(error.exception),
         )
 
     @client_context.require_failCommand_appName
@@ -505,9 +505,9 @@ def test_connection_timeout_message(self):
             with self.assertRaises(Exception) as error:
                 client.admin.command("ping")
 
-        self.assertTrue(
-            "(configured timeouts: socketTimeoutMS: 500.0ms, connectTimeoutMS: 500.0ms)"
-            in str(error.exception)
+        self.assertIn(
+            "(configured timeouts: socketTimeoutMS: 500.0ms, connectTimeoutMS: 500.0ms)",
+            str(error.exception),
         )
 
 
diff --git a/test/test_server.py b/test/test_server.py
index 45d01c10de..ab5a40a79b 100644
--- a/test/test_server.py
+++ b/test/test_server.py
@@ -31,7 +31,7 @@ def test_repr(self):
         hello = Hello({"ok": 1})
         sd = ServerDescription(("localhost", 27017), hello)
         server = Server(sd, pool=object(), monitor=object())  # type: ignore[arg-type]
-        self.assertTrue("Standalone" in str(server))
+        self.assertIn("Standalone", str(server))
 
 
 if __name__ == "__main__":