diff --git a/tests/utils/test_core.py b/tests/utils/test_core.py
index 879100428..4bcdf0e88 100644
--- a/tests/utils/test_core.py
+++ b/tests/utils/test_core.py
@@ -71,7 +71,7 @@ class StrokeWidthValue(ValueChannel, schemapi.SchemaBase):
 
 
 @pytest.mark.parametrize(
-    "value,expected_type",
+    ("value", "expected_type"),
     [
         ([1, 2, 3], "integer"),
         ([1.0, 2.0, 3.0], "floating"),
diff --git a/tests/utils/test_schemapi.py b/tests/utils/test_schemapi.py
index e95b11048..9cc201c6b 100644
--- a/tests/utils/test_schemapi.py
+++ b/tests/utils/test_schemapi.py
@@ -645,7 +645,7 @@ def chart_error_example__four_errors():
 
 
 @pytest.mark.parametrize(
-    "chart_func, expected_error_message",
+    ("chart_func", "expected_error_message"),
     [
         (
             chart_error_example__invalid_y_option_value_unknown_x_option,
diff --git a/tests/vegalite/v5/test_api.py b/tests/vegalite/v5/test_api.py
index b8c4b5ea4..4458d7aa8 100644
--- a/tests/vegalite/v5/test_api.py
+++ b/tests/vegalite/v5/test_api.py
@@ -190,7 +190,7 @@ def _check_encodings(chart):
 
 
 @pytest.mark.parametrize(
-    "args, kwargs",
+    ("args", "kwargs"),
     [
         getargs(detail=["value:Q", "name:N"], tooltip=["value:Q", "name:N"]),
         getargs(detail=["value", "name"], tooltip=["value", "name"]),