diff --git a/docs/writing-tests/testdriver.md b/docs/writing-tests/testdriver.md
index ca24a345beb58c..c2787b6be90db4 100644
--- a/docs/writing-tests/testdriver.md
+++ b/docs/writing-tests/testdriver.md
@@ -38,7 +38,7 @@ The api in `test_driver.bidi` provides access to the
 
 ### Markup ###
 
-To use WebDriver BiDi, enable the `bidi` feature in `testdriver.js` by adding
+To use WebDriver BiDi, enable the `bidi` feature in `testdriver.js` by adding the
 `feature=bidi` query string parameter. Details are in [RFC 214: Add testdriver features](https://github.com/web-platform-tests/rfcs/blob/master/rfcs/testdriver-features.md).
 ```html
 <script src="/resources/testdriver.js?feature=bidi"></script>
diff --git a/tools/lint/lint.py b/tools/lint/lint.py
index 9447bb3f914639..1228d546e01ac6 100644
--- a/tools/lint/lint.py
+++ b/tools/lint/lint.py
@@ -524,16 +524,23 @@ def check_parsed(repo_root: Text, path: Text, f: IO[bytes]) -> List[rules.Error]
         src = element.attrib["src"]
 
         def is_path_correct(script: Text, src: Text) -> bool:
+            """
+            If the `src` relevant to the `script`, check that the `src` is the
+            correct path for `script`.
+            :param script: the script name to check the `src` for.
+            :param src: the included path.
+            :return: if the `src` irrelevant to the `script`, or if the `src`
+                     path is the correct path.
+            """
             if script == src:
                 # The src does not provide the full path.
                 return False
 
             if "/%s" % script not in src:
-                # The src is not related to the script.
+                # The src is not relevant to the script.
                 return True
 
-            return src == "/resources/%s" % script or ("%s" % src).startswith(
-                "/resources/%s?" % script)
+            return ("%s" % src).startswith("/resources/%s" % script)
 
         def is_query_string_correct(script: Text, src: Text,
                 allowed_query_string_params: Dict[str, List[str]]) -> bool:
@@ -553,7 +560,7 @@ def is_query_string_correct(script: Text, src: Text,
                                                 allowed parameter names and
                                                 values are lists of allowed
                                                 values for each parameter.
-            :return: if the query string does not contain any not-allowed
+            :return: if the query string is empty or contains only allowed
                      params.
             """
             if not ("%s" % src).startswith("/resources/%s?" % script):
@@ -569,10 +576,6 @@ def is_query_string_correct(script: Text, src: Text,
                 return False
 
             for param_name in query_string_params:
-                if ':' in param_name:
-                    # Allow for vendor-specific query parameters.
-                    continue
-
                 if param_name not in allowed_query_string_params:
                     return False
 
diff --git a/tools/lint/rules.py b/tools/lint/rules.py
index c86f3943500ffc..6f3bacf49b99d5 100644
--- a/tools/lint/rules.py
+++ b/tools/lint/rules.py
@@ -276,7 +276,7 @@ class TestdriverPath(Rule):
 
 class TestdriverUnsupportedQueryParameter(Rule):
     name = "TESTDRIVER-UNSUPPORTED-QUERY-PARAMETER"
-    description = "testdriver.js script seen with incorrect query parameters"
+    description = "testdriver.js script seen with unsupported query parameters"
 
 
 class TestdriverVendorPath(Rule):
diff --git a/tools/lint/tests/test_file_lints.py b/tools/lint/tests/test_file_lints.py
index 1ede163fad8f50..92270e38a69d70 100644
--- a/tools/lint/tests/test_file_lints.py
+++ b/tools/lint/tests/test_file_lints.py
@@ -508,7 +508,7 @@ def test_testdriver_unsupported_query_param():
         if kind in ["web-lax", "web-strict"]:
             assert errors == [
                 ("TESTDRIVER-UNSUPPORTED-QUERY-PARAMETER",
-                 "testdriver.js script seen with incorrect query parameters",
+                 "testdriver.js script seen with unsupported query parameters",
                  filename, None),
             ]
         elif kind == "python":
@@ -532,7 +532,11 @@ def test_testdriver_vendor_query_param():
         check_errors(errors)
 
         if kind in ["web-lax", "web-strict"]:
-            assert errors == []
+            assert errors == [
+                ('TESTDRIVER-UNSUPPORTED-QUERY-PARAMETER',
+                 'testdriver.js script seen with unsupported query parameters',
+                 filename, None)
+            ]
         elif kind == "python":
             assert errors == [
                 ("PARSE-FAILED", "Unable to parse file", filename, 2),
@@ -556,7 +560,7 @@ def test_testdriver_unsupported_feature():
         if kind in ["web-lax", "web-strict"]:
             assert errors == [
                 ("TESTDRIVER-UNSUPPORTED-QUERY-PARAMETER",
-                 "testdriver.js script seen with incorrect query parameters",
+                 "testdriver.js script seen with unsupported query parameters",
                  filename, None),
             ]
         elif kind == "python":
@@ -565,7 +569,7 @@ def test_testdriver_unsupported_feature():
             ]
 
 
-def test_testdriver_multiple_unsupported_features():
+def test_testdriver_multiple_with_unsupported_features():
     code = b"""
 <html xmlns="http://www.w3.org/1999/xhtml">
 <script src="/resources/testharness.js"></script>
@@ -582,7 +586,7 @@ def test_testdriver_multiple_unsupported_features():
         if kind == "web-lax":
             assert errors == [
                 ('TESTDRIVER-UNSUPPORTED-QUERY-PARAMETER',
-                 'testdriver.js script seen with incorrect query parameters',
+                 'testdriver.js script seen with unsupported query parameters',
                  filename, None)
             ]
         elif kind == "python":
@@ -660,7 +664,7 @@ def test_testdriver_unsupported_empty_feature():
         if kind in ["web-lax", "web-strict"]:
             assert errors == [
                 ("TESTDRIVER-UNSUPPORTED-QUERY-PARAMETER",
-                 "testdriver.js script seen with incorrect query parameters",
+                 "testdriver.js script seen with unsupported query parameters",
                  filename, None),
             ]
         elif kind == "python":