diff --git a/Lib/python/pyrun.swg b/Lib/python/pyrun.swg
index 1716aa56a..e1924a1a4 100644
--- a/Lib/python/pyrun.swg
+++ b/Lib/python/pyrun.swg
@@ -429,7 +429,7 @@ SwigPyObject_repr(SwigPyObject *v, PyObject *args)
 #endif
 {
   const char *name = SWIG_TypePrettyName(v->ty);
-  PyObject *repr = SWIG_Python_str_FromFormat("<Swig Object of type '%s' at %p>", name, (void *)v);
+  PyObject *repr = SWIG_Python_str_FromFormat("<Swig Object of type '%s' at %p>", (name ? name : "unknown"), (void *)v);
   if (v->next) {
 # ifdef METH_NOARGS
     PyObject *nrep = SwigPyObject_repr((SwigPyObject *)v->next);