diff --git a/Objects/complexobject.c b/Objects/complexobject.c
index c47e0d3..5999796 100644
--- a/Objects/complexobject.c
+++ b/Objects/complexobject.c
@@ -783,7 +783,7 @@
     }
     else if (PyObject_AsCharBuffer(v, &s, &len)) {
         PyErr_SetString(PyExc_TypeError,
-                        "complex() arg is not a string");
+                        "complex() argument must be a string or a number");
         return NULL;
     }