diff --git a/Lib/pydoc.py b/Lib/pydoc.py
index 674af6a..68ba21f 100755
--- a/Lib/pydoc.py
+++ b/Lib/pydoc.py
@@ -1498,7 +1498,8 @@
             raise ImportError, 'no Python documentation found for %r' % thing
         return object, thing
     else:
-        return thing, getattr(thing, '__name__', None)
+        name = getattr(thing, '__name__', None)
+        return thing, name if isinstance(name, str) else None
 
 def render_doc(thing, title='Python Library Documentation: %s', forceload=0):
     """Render text documentation, given an object or a path to an object."""
diff --git a/Lib/test/test_pydoc.py b/Lib/test/test_pydoc.py
index 59cbffe..d95e706 100644
--- a/Lib/test/test_pydoc.py
+++ b/Lib/test/test_pydoc.py
@@ -249,6 +249,17 @@
         result, doc_loc = get_pydoc_text(xml.etree)
         self.assertEqual(doc_loc, "", "MODULE DOCS incorrectly includes a link")
 
+    def test_non_str_name(self):
+        # issue14638
+        # Treat illegal (non-str) name like no name
+        class A:
+            __name__ = 42
+        class B:
+            pass
+        adoc = pydoc.render_doc(A())
+        bdoc = pydoc.render_doc(B())
+        self.assertEqual(adoc.replace("A", "B"), bdoc)
+
     def test_not_here(self):
         missing_module = "test.i_am_not_here"
         result = run_pydoc(missing_module)