diff --git a/Objects/abstract.c b/Objects/abstract.c
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -259,7 +259,7 @@
          pb->bf_getcharbuffer == NULL ||
          pb->bf_getsegcount == NULL) {
         PyErr_SetString(PyExc_TypeError,
-                        "expected a character buffer object");
+                        "expected a character buffer object (such as a string)");
         return -1;
     }
     if ((*pb->bf_getsegcount)(obj,NULL) != 1) {