diff --git a/Modules/_codecsmodule.c b/Modules/_codecsmodule.c
index 5b50144..3b07b6d 100644
--- a/Modules/_codecsmodule.c
+++ b/Modules/_codecsmodule.c
@@ -179,12 +179,13 @@
     PyObject *str;
     const char *errors = NULL;
     char *buf;
-    Py_ssize_t len;
+    Py_ssize_t consumed, len;
 
-    if (!PyArg_ParseTuple(args, "O!|z:escape_encode",
-                          &PyString_Type, &str, &errors))
+    if (!PyArg_ParseTuple(args, "S|z:escape_encode",
+                          &str, &errors))
         return NULL;
 
+    consumed = PyString_GET_SIZE(str);
     str = PyString_Repr(str, 0);
     if (!str)
         return NULL;
@@ -196,7 +197,7 @@
     if (_PyString_Resize(&str, len-2) < 0)
         return NULL;
 
-    return codec_tuple(str, PyString_Size(str));
+    return codec_tuple(str, consumed);
 }
 
 #ifdef Py_USING_UNICODE