diff --git a/tests/test_builtin_casters.py b/tests/test_builtin_casters.py
index 64d2f1945..bc094a381 100644
--- a/tests/test_builtin_casters.py
+++ b/tests/test_builtin_casters.py
@@ -151,10 +151,10 @@ def test_integer_casting():
     assert m.i32_str(2000000000) == "2000000000"
     assert m.u32_str(2000000000) == "2000000000"
     if sys.version_info < (3,):
-        assert m.i32_str(long(-1)) == "-1"
-        assert m.i64_str(long(-1)) == "-1"
-        assert m.i64_str(long(-999999999999)) == "-999999999999"
-        assert m.u64_str(long(999999999999)) == "999999999999"
+        assert m.i32_str(long(-1)) == "-1"  # noqa: F821 undefined name 'long'
+        assert m.i64_str(long(-1)) == "-1"  # noqa: F821 undefined name 'long'
+        assert m.i64_str(long(-999999999999)) == "-999999999999"  # noqa: F821 undefined name
+        assert m.u64_str(long(999999999999)) == "999999999999"  # noqa: F821 undefined name 'long'
     else:
         assert m.i64_str(-999999999999) == "-999999999999"
         assert m.u64_str(999999999999) == "999999999999"
@@ -174,10 +174,10 @@ def test_integer_casting():
 
     if sys.version_info < (3,):
         with pytest.raises(TypeError) as excinfo:
-            m.u32_str(long(-1))
+            m.u32_str(long(-1))  # noqa: F821 undefined name 'long'
         assert "incompatible function arguments" in str(excinfo.value)
         with pytest.raises(TypeError) as excinfo:
-            m.u64_str(long(-1))
+            m.u64_str(long(-1))  # noqa: F821 undefined name 'long'
         assert "incompatible function arguments" in str(excinfo.value)