1 files changed, 3 insertions, 0 deletions
diff --git a/Cython/Utility/CythonFunction.c b/Cython/Utility/CythonFunction.c
index 5ea48ea94..b2c67dcce 100644
--- a/Cython/Utility/CythonFunction.c
+++ b/Cython/Utility/CythonFunction.c
@@ -660,6 +660,9 @@ static PyObject *__Pyx_CyFunction_CallAsMethod(PyObject *func, PyObject *args, P
         self = PyTuple_GetItem(args, 0);
         if (unlikely(!self)) {
             Py_DECREF(new_args);
+            PyErr_Format(PyExc_TypeError,
+                         "unbound method %.200S() needs an argument",
+                         cyfunc->func_qualname);
             return NULL;
         }