diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index e6c14f8..438f760 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -417,6 +417,9 @@
 {
     PyObject *result = STRING_CONV_FUNC(str);
     PyObject *value;
+    /* result can be NULL if the unicode conversion failed. */
+    if (!result)
+	return result;
     if (!self->intern)
 	return result;
     value = PyDict_GetItem(self->intern, result);
@@ -572,7 +575,9 @@
                 Py_DECREF(v);
             }
         }
-	args = Py_BuildValue("(NN)", string_intern(self, name), container);
+        args = string_intern(self, name);
+        if (args != NULL)
+            args = Py_BuildValue("(NN)", args, container);
         if (args == NULL) {
             Py_DECREF(container);
             return;