diff -r 2fe0b2dcc98c Objects/bytesobject.c
--- a/Objects/bytesobject.c	Tue Jan 21 15:36:51 2014 -0500
+++ b/Objects/bytesobject.c	Tue Jan 21 23:10:32 2014 +0100
@@ -2557,6 +2557,13 @@
         return new;
     }
 
+    /* If it's not unicode, there can't be encoding or errors */
+    if (encoding != NULL || errors != NULL) {
+        PyErr_SetString(PyExc_TypeError,
+            "encoding or errors without a string argument");
+        return NULL;
+    }
+
     /* We'd like to call PyObject_Bytes here, but we need to check for an
        integer argument before deferring to PyBytes_FromObject, something
        PyObject_Bytes doesn't do. */
@@ -2598,13 +2605,6 @@
         return new;
     }
 
-    /* If it's not unicode, there can't be encoding or errors */
-    if (encoding != NULL || errors != NULL) {
-        PyErr_SetString(PyExc_TypeError,
-            "encoding or errors without a string argument");
-        return NULL;
-    }
-
     return PyBytes_FromObject(x);
 }