diff --git a/importlib_metadata/__init__.py b/importlib_metadata/__init__.py
index 8d9f0016..e44ea31a 100644
--- a/importlib_metadata/__init__.py
+++ b/importlib_metadata/__init__.py
@@ -902,4 +902,9 @@ def _top_level_inferred(dist):
         f.parts[0] if len(f.parts) > 1 else inspect.getmodulename(f)
         for f in always_iterable(dist.files)
     }
-    return filter(None, opt_names)
+
+    @pass_none
+    def valid_module(name):
+        return name.isidentifier()
+
+    return filter(valid_module, opt_names)
diff --git a/tests/test_main.py b/tests/test_main.py
index 73747405..ba752d88 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -323,9 +323,6 @@ def test_packages_distributions_neither_toplevel_nor_files(self):
         )
         packages_distributions()
 
-    import pytest
-
-    @pytest.mark.xfail(reason="442")
     def test_packages_distributions_all_module_types(self):
         """
         Test top-level modules detected on a package without 'top-level.txt'.