diff --git a/README.md b/README.md
index e06e075..a9744e6 100644
--- a/README.md
+++ b/README.md
@@ -85,8 +85,10 @@ tb.tests.stop_test(sessionId)
 tb.tests.delete_test(sessionId)
 
 # Create a record for a manual / external test result
-tb.tests.create_test(name, success=None, status_message=None,
-                     extra=None, build=None)
+tb.tests.create_test(name, test_environment_id=browserId, success=None,
+                     status_message=None, extra=None, build=None)
+# test_environment_id is required by the API: the `browser_id` of the browser/device
+# the test ran on, from tb.information.get_browsers()
 ```
 
 ## Builds — `tb.build`
diff --git a/testingbotclient.py b/testingbotclient.py
index 15cb7c0..1afd159 100644
--- a/testingbotclient.py
+++ b/testingbotclient.py
@@ -226,9 +226,17 @@ def get_test(self, sessionId: Union[int, str], skip_fields: Optional[Union[list,
         return self.client.get(url)
 
     def create_test(self, name: str, success: Optional[bool] = None, status_message: Optional[str] = None,
-                    extra: Optional[str] = None, build: Optional[str] = None) -> Any:
-        """Create a test record (for logging manual or external test results)."""
+                    extra: Optional[str] = None, build: Optional[str] = None,
+                    test_environment_id: Optional[Union[int, str]] = None) -> Any:
+        """Create a test record (for logging manual or external test results).
+
+        test_environment_id: the ``browser_id`` of the browser/device (from
+        ``tb.information.get_browsers()``) the test ran on. The API rejects
+        the request without it.
+        """
         test = {'name': name}
+        if test_environment_id is not None:
+            test['test_environment_id'] = test_environment_id
         if success is not None:
             test['success'] = success
         if status_message is not None:
diff --git a/tests/test_unit.py b/tests/test_unit.py
index d370b13..7220298 100644
--- a/tests/test_unit.py
+++ b/tests/test_unit.py
@@ -259,6 +259,14 @@ def test_create_test(self):
             'status_message': 'm', 'build': 'b1'}})
         self.assertEqual(out, {'success': True})
 
+    def test_create_test_with_environment(self):
+        self.queue(200, {'success': True})
+        self.client.tests.create_test('manual run', success=True,
+                                      test_environment_id=1)
+        self.assertCall('POST', '/tests', json_body={'test': {
+            'name': 'manual run', 'test_environment_id': 1,
+            'success': True}})
+
     def test_update_test_pass(self):
         self.queue(200, {'success': True})
         ok = self.client.tests.update_test('s', name='n', passed=True,