diff --git a/schwab/client/asynchronous.py b/schwab/client/asynchronous.py
index fffd77b..2cbc34c 100644
--- a/schwab/client/asynchronous.py
+++ b/schwab/client/asynchronous.py
@@ -49,18 +49,6 @@ async def _put_request(self, path, data):
         register_redactions_from_response(resp)
         return resp
 
-    async def _patch_request(self, path, data):
-        dest = 'https://api.schwabapi.com' + path
-
-        req_num = self._req_num()
-        self.logger.debug('Req %s: PATCH to %s, json=%s',
-                req_num, dest, LazyLog(lambda: json.dumps(data, indent=4)))
-
-        resp = await self.session.patch(dest, json=data)
-        self._log_response(resp, req_num)
-        register_redactions_from_response(resp)
-        return resp
-
     async def _delete_request(self, path):
         dest = 'https://api.schwabapi.com' + path
 
diff --git a/schwab/client/synchronous.py b/schwab/client/synchronous.py
index 7014148..c584b3b 100644
--- a/schwab/client/synchronous.py
+++ b/schwab/client/synchronous.py
@@ -45,18 +45,6 @@ def _put_request(self, path, data):
         register_redactions_from_response(resp)
         return resp
 
-    def _patch_request(self, path, data):
-        dest = 'https://api.schwabapi.com' + path
-
-        req_num = self._req_num()
-        self.logger.debug('Req %s: PATCH to %s, json=%s',
-                req_num, dest, LazyLog(lambda: json.dumps(data, indent=4)))
-
-        resp = self.session.patch(dest, json=data)
-        self._log_response(resp, req_num)
-        register_redactions_from_response(resp)
-        return resp
-
     def _delete_request(self, path):
         dest = 'https://api.schwabapi.com' + path
 
diff --git a/tests/client_test.py b/tests/client_test.py
index 7aff57d..c205838 100644
--- a/tests/client_test.py
+++ b/tests/client_test.py
@@ -457,6 +457,26 @@ def test_replace_order_str(self):
             json=order_spec)
 
 
+    # preview_order
+
+    
+    def test_preview_order(self):
+        order_spec = {'order': 'spec'}
+        self.client.preview_order(ACCOUNT_HASH, order_spec)
+        self.mock_session.post.assert_called_once_with(
+            self.make_url('/trader/v1/accounts/{accountHash}/previewOrder'),
+            json=order_spec)
+
+    
+    def test_preview_order_order_builder(self):
+        order_spec = OrderBuilder(enforce_enums=False).set_order_type('LIMIT')
+        expected_spec = {'orderType': 'LIMIT'}
+        self.client.preview_order(ACCOUNT_HASH, order_spec)
+        self.mock_session.post.assert_called_once_with(
+            self.make_url('/trader/v1/accounts/{accountHash}/previewOrder'),
+            json=expected_spec)
+
+    
     # get_transactions