diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -3054,8 +3054,9 @@
         goto onError;
     if (!PyUnicode_Check(unicode)) {
         PyErr_Format(PyExc_TypeError,
-                     "decoder did not return a str object (type=%.400s)",
-                     Py_TYPE(unicode)->tp_name);
+                     "decoder returned '%.400s' instead of 'str', "
+                     "use codecs.encode for bytes->%.400s conversions",
+                     Py_TYPE(unicode)->tp_name, Py_TYPE(unicode)->tp_name);
         Py_DECREF(unicode);
         goto onError;
     }
@@ -3437,8 +3438,9 @@
     }
 
     PyErr_Format(PyExc_TypeError,
-                 "encoder did not return a bytes object (type=%.400s)",
-                 Py_TYPE(v)->tp_name);
+                 "encoder returned '%.400s' instead of 'bytes', "
+                 "use codecs.decode for str->%.400s conversions",
+                 Py_TYPE(v)->tp_name, Py_TYPE(v)->tp_name);
     Py_DECREF(v);
     return NULL;
 }
@@ -10933,11 +10935,26 @@
     static char *kwlist[] = {"encoding", "errors", 0};
     char *encoding = NULL;
     char *errors = NULL;
+    PyObject *result;
+    PyObject *exc = NULL, *val, *tb;
 
     if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|ss:encode",
                                      kwlist, &encoding, &errors))
         return NULL;
-    return PyUnicode_AsEncodedString(self, encoding, errors);
+    result = PyUnicode_AsEncodedString(self, encoding, errors);
+    if (result == NULL) {
+        if (PyErr_ExceptionMatches(PyExc_TypeError)) {
+            PyErr_Fetch(&exc, &val, &tb);
+            PyErr_Format(PyExc_TypeError, "invalid input type for %s codec (%U)",
+                         encoding, val);
+        }
+        else if (PyErr_ExceptionMatches(PyExc_ValueError)) {
+            PyErr_Fetch(&exc, &val, &tb);
+            PyErr_Format(PyExc_ValueError, "invalid input value for %s codec (%U)",
+                         encoding, val);
+        }
+    }
+    return result;
 }
 
 PyDoc_STRVAR(expandtabs__doc__,