diff -r d433d74e0377 Objects/unicodeobject.c
--- a/Objects/unicodeobject.c	Thu Sep 10 16:00:06 2015 +0200
+++ b/Objects/unicodeobject.c	Thu Sep 10 21:15:23 2015 +0200
@@ -3929,6 +3929,23 @@ PyUnicode_GetDefaultEncoding(void)
     return "utf-8";
 }
 
+#define _Py_CODEC_ERROR_UNKNOWN 0
+#define _Py_CODEC_ERROR_SURROGATEPASS 1
+#define _Py_CODEC_ERROR_SURROGATEESCAPE 2
+#define _Py_CODEC_ERROR_OTHER -1
+
+static int
+detect_standard_errorhandler(const char *errors)
+{
+    if (errors == NULL)
+        return _Py_CODEC_ERROR_OTHER;  /* strict */
+    if (strcmp(errors, "surrogatepass") == 0)
+        return _Py_CODEC_ERROR_SURROGATEPASS;
+    if (strcmp(errors, "surrogateescape") == 0)
+        return _Py_CODEC_ERROR_SURROGATEESCAPE;
+    return _Py_CODEC_ERROR_OTHER;
+}
+
 /* create or adjust a UnicodeDecodeError */
 static void
 make_decode_exception(PyObject **exceptionObject,
@@ -6659,6 +6676,7 @@ PyUnicode_DecodeASCII(const char *s,
     const char *e;
     PyObject *errorHandler = NULL;
     PyObject *exc = NULL;
+    int errorType = _Py_CODEC_ERROR_UNKNOWN;
 
     if (size == 0)
         _Py_RETURN_UNICODE_EMPTY();
@@ -6689,6 +6707,23 @@ PyUnicode_DecodeASCII(const char *s,
             ++s;
         }
         else {
+            if (errorType == _Py_CODEC_ERROR_UNKNOWN) {
+                errorType = detect_standard_errorhandler(errors);
+                if (errorType == _Py_CODEC_ERROR_SURROGATEESCAPE &&
+                    kind < PyUnicode_2BYTE_KIND) {
+                    if (_PyUnicodeWriter_Prepare(&writer, size - writer.pos, 0xffff) < 0)
+                        return NULL;
+                    kind = writer.kind;
+                    data = writer.data;
+                }
+            }
+            if (errorType == _Py_CODEC_ERROR_SURROGATEESCAPE) {
+                PyUnicode_WRITE(kind, data, writer.pos, c + 0xdc00);
+                writer.pos++;
+                ++s;
+                continue;
+            }
+
             startinpos = s-starts;
             endinpos = startinpos + 1;
             if (unicode_decode_call_errorhandler_writer(