diff --git a/pasn1.py b/pasn1.py
index baef577..6066a0a 100644
--- a/pasn1.py
+++ b/pasn1.py
@@ -161,7 +161,7 @@ class ASN1Coder(object):
 	_typetag = dict((v, k) for k, v in _tagmap.iteritems())
 
 	@staticmethod
-	def enc_int(obj):
+	def enc_int(obj, **kwargs):
 		l = obj.bit_length()
 		l += 1	# space for sign bit
 
@@ -190,7 +190,7 @@ class ASN1Coder(object):
 		return v, end
 
 	@staticmethod
-	def enc_bool(obj):
+	def enc_bool(obj, **kwargs):
 		return '\x01' + ('\xff' if obj else '\x00')
 
 	def dec_bool(self, d, pos, end):
@@ -201,15 +201,15 @@ class ASN1Coder(object):
 		return bool(v), end
 
 	@staticmethod
-	def enc_null(obj):
+	def enc_null(obj, **kwargs):
 		return '\x00'
 
 	@staticmethod
 	def dec_null(d, pos, end):
 		return None, end
 
-	def enc_list(self, obj):
-		r = ''.join(self.dumps(x) for x in obj)
+	def enc_list(self, obj, **kwargs):
+		r = ''.join(self.dumps(x, **kwargs) for x in obj)
 		return _encodelen(len(r)) + r
 
 	def dec_list(self, d, pos, end):
@@ -231,7 +231,7 @@ class ASN1Coder(object):
 		return set(r), end
 
 	@staticmethod
-	def enc_bytes(obj):
+	def enc_bytes(obj, **kwargs):
 		return _encodelen(len(obj)) + bytes(obj)
 
 	@staticmethod
@@ -239,7 +239,7 @@ class ASN1Coder(object):
 		return d[pos:end], end
 
 	@staticmethod
-	def enc_unicode(obj):
+	def enc_unicode(obj, **kwargs):
 		encobj = obj.encode('utf-8')
 		return _encodelen(len(encobj)) + encobj
 
@@ -247,7 +247,7 @@ class ASN1Coder(object):
 		return d[pos:end].decode('utf-8'), end
 
 	@staticmethod
-	def enc_float(obj):
+	def enc_float(obj, **kwargs):
 		s = math.copysign(1, obj)
 		if math.isnan(obj):
 			return _encodelen(1) + chr(0b01000010)
@@ -335,7 +335,7 @@ class ASN1Coder(object):
 		except KeyError:
 			if default is not None:
 				try:
-					return self.dumps(default(obj))
+					return self.dumps(default(obj), default=default)
 				except TypeError:
 					pass
 
@@ -345,7 +345,7 @@ class ASN1Coder(object):
 			tf, obj = self.coerce(obj)
 
 		fun = getattr(self, 'enc_%s' % tf)
-		return self._typetag[tf] + fun(obj)
+		return self._typetag[tf] + fun(obj, default=default)
 
 	def _loads(self, data, pos, end):
 		tag = data[pos]
@@ -360,7 +360,7 @@ class ASN1Coder(object):
 		fun = getattr(self, 'dec_%s' % t)
 		return fun(data, pos + 1 + b, end)
 
-	def enc_datetime(self, obj):
+	def enc_datetime(self, obj, **kwargs):
 		ts = obj.strftime('%Y%m%d%H%M%S')
 		if obj.microsecond:
 			ts += ('.%06d' % obj.microsecond).rstrip('0')
@@ -414,10 +414,10 @@ class ASN1DictCoder(ASN1Coder):
 	_tagmap['\xe0'] = 'dict'
 	_typetag = dict((v, k) for k, v in _tagmap.iteritems())
 
-	def enc_dict(self, obj):
+	def enc_dict(self, obj, **kwargs):
 		#it = list(obj.iteritems())
 		#it.sort()
-		r = ''.join(self.dumps(k) + self.dumps(v) for k, v in
+		r = ''.join(self.dumps(k, **kwargs) + self.dumps(v, **kwargs) for k, v in
 		    obj.iteritems())
 		return _encodelen(len(r)) + r
 
@@ -667,6 +667,10 @@ class TestCode(unittest.TestCase):
 			def somefun(self):
 				return 5
 
+		class Dummy2(object):
+			def somefun(self):
+				return [ Dummy() ]
+
 		def deffun(obj):
 			try:
 				return obj.somefun()
@@ -674,5 +678,12 @@ class TestCode(unittest.TestCase):
 				raise TypeError
 
 		self.assertEqual(dumps(5), dumps(Dummy(), default=deffun))
-		# XXX make subobjects work
+
+		# Make sure it works for the various containers
 		self.assertEqual(dumps([5]), dumps([Dummy()], default=deffun))
+		self.assertEqual(dumps({ 5: 5 }), dumps({ Dummy(): Dummy() },
+		    default=deffun))
+		self.assertEqual(dumps([5]), dumps(Dummy2(), default=deffun))
+
+		# Make sure that an error is raised when the function doesn't work
+		self.assertRaises(TypeError, dumps, object(), default=deffun)