diff --git a/Milter/__init__.py b/Milter/__init__.py
index 542be0b..7e09328 100755
--- a/Milter/__init__.py
+++ b/Milter/__init__.py
@@ -327,7 +327,9 @@ class Base(object):
   # to pass bytes to @link #header the header callback @endlink instead,
   # or trap utf-8 conversion exception, etc.
   def envfrom_bytes(self,*b):
-    s = (v.decode(encoding='utf-8',errors='surrogateescape') for v in b)
+    try:
+      s = (v.decode(encoding='utf-8') for v in b)
+    except UnicodeDecodeError: s = b
     return self.envfrom(fld,*s)
   ## Called when the SMTP client says MAIL FROM. Called by the
   # <a href="milter_api/xxfi_envfrom.html">
@@ -346,7 +348,9 @@ class Base(object):
   # to pass bytes to @link #header the header callback @endlink instead,
   # or trap utf-8 conversion exception, etc.
   def envrcpt_bytes(self,*b):
-    s = (v.decode(encoding='utf-8',errors='surrogateescape') for v in b)
+    try:
+      s = (v.decode(encoding='utf-8') for v in b)
+    except UnicodeDecodeError: s = b
     return self.envrcpt(fld,*s)
   ## Called when the SMTP client says RCPT TO. Called by the
   # <a href="milter_api/xxfi_envrcpt.html">
@@ -372,7 +376,9 @@ class Base(object):
   # Converts from utf-8 to unicode with surrogate escape.  Can be overriden 
   # to pass bytes to @link #header the header callback @endlink instead.
   def header_bytes(self,fld,val):
-    s = val.decode(encoding='utf-8',errors='surrogateescape')
+    try:
+      s = val.decode(encoding='utf-8')
+    except UnicodeDecodeError: s = val
     return self.header(fld,s)
   ## Called for each header field in the message body.
   # @param field name decoded as ascii
diff --git a/Milter/testctx.py b/Milter/testctx.py
index 4225615..7235694 100644
--- a/Milter/testctx.py
+++ b/Milter/testctx.py
@@ -234,7 +234,7 @@ class TestCtx(object):
     else:
       v = val.encode(encoding='ascii',errors='surrogateescape')
     # invoke the Milter header_callback
-    return Milter.header_callback(self,fld,v)
+    return self._priv.header_bytes(fld,v)
 
   def _eoh(self):
     if self._protocol & Milter.P_NOEOH:
diff --git a/miltermodule.c b/miltermodule.c
index f7422e2..07708ef 100644
--- a/miltermodule.c
+++ b/miltermodule.c
@@ -250,7 +250,7 @@ static const char milter_set_flags__doc__[] =
 Set flags for filter capabilities; OR of one or more of:\n\
 ADDHDRS - filter may add headers\n\
 CHGBODY - filter may replace body\n\
-CHGFROM - filter may replace body\n\
+CHGFROM - filter may replace sender\n\
 ADDRCPT - filter may add recipients\n\
 DELRCPT - filter may delete recipients\n\
 CHGHDRS - filter may change/delete headers";
diff --git a/sample.py b/sample.py
index 9565591..031c22d 100644
--- a/sample.py
+++ b/sample.py
@@ -73,6 +73,7 @@ class sampleMilter(Milter.Milter):
 
       # even if we wanted the Taiwanese spam, we can't read Chinese
       # (delete if you read chinese mail)
+      print('val=',val)
       if val.startswith('=?big5') or val.startswith('=?ISO-2022-JP'):
         self.log('REJECT: %s: %s' % (name,val))
 	#self.setreply('550','','Go away spammer')