diff --git a/pyproject.toml b/pyproject.toml
index 8b1d0e15a9..abc09835c1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -187,6 +187,7 @@ exclude_also = [
     '''if (t\.)?TYPE_CHECKING:''',
 ]
 fail_under = 82
+show_missing = true
 
 [tool.mypy]
 exclude = "tests"
diff --git a/tests/core/test_plugin_base.py b/tests/core/test_plugin_base.py
index 7d1021c112..0ea87f0368 100644
--- a/tests/core/test_plugin_base.py
+++ b/tests/core/test_plugin_base.py
@@ -5,7 +5,7 @@
 
 import pytest
 
-from singer_sdk.plugin_base import MapperNotInitialized, PluginBase
+from singer_sdk.plugin_base import SDK_PACKAGE_NAME, MapperNotInitialized, PluginBase
 from singer_sdk.typing import IntegerType, PropertiesList, Property, StringType
 
 
@@ -53,3 +53,8 @@ def test_mapper_not_initialized():
     )
     with pytest.raises(MapperNotInitialized):
         _ = plugin.mapper
+
+
+def test_supported_python_versions():
+    """Test that supported python versions are correctly parsed."""
+    assert PluginBase._get_supported_python_versions(SDK_PACKAGE_NAME)