diff --git a/spacy/serialize.pxd b/spacy/serialize.pxd
index df7f0fc65..d060382a4 100644
--- a/spacy/serialize.pxd
+++ b/spacy/serialize.pxd
@@ -4,6 +4,8 @@ from libc.stdint cimport int64_t
 from libc.stdint cimport int32_t
 from libc.stdint cimport uint64_t
 
+from .vocab cimport Vocab
+
 
 cdef struct Node:
     float prob
@@ -18,6 +20,7 @@ cdef struct Code:
 
 cdef class Serializer:
     cdef list codecs
+    cdef Vocab vocab
 
 
 cdef class HuffmanCodec:
diff --git a/spacy/serialize.pyx b/spacy/serialize.pyx
index a354203d4..de217f74e 100644
--- a/spacy/serialize.pyx
+++ b/spacy/serialize.pyx
@@ -3,10 +3,15 @@ from libc.stdint cimport uint32_t
 from libc.stdint cimport int64_t
 from libc.stdint cimport int32_t
 from libc.stdint cimport uint64_t
+from libcpp.queue cimport priority_queue
+from libcpp.pair cimport pair
 
 from preshed.maps cimport PreshMap
 from murmurhash.mrmr cimport hash64
+from .tokens.doc cimport Doc
+from .vocab cimport Vocab
 
+from os import path
 import numpy
 
 cimport cython
@@ -97,7 +102,7 @@ cdef class Serializer:
     def __init__(self, Vocab vocab, data_dir):
         model_dir = path.join(data_dir, 'bitter')
         self.vocab = vocab # Vocab owns the word codec, the big one
-        self.cfg = Config.read(model_dir, 'config')
+        #self.cfg = Config.read(model_dir, 'config')
         self.codecs = tuple([CodecWrapper(attr) for attr in self.cfg.attrs])
 
     def __call__(self, doc_or_bits):
@@ -129,7 +134,7 @@ cdef class Serializer:
         cdef bint is_spacy
         for id_ in ids:
             is_spacy = biterator.next()
-            doc.push_back(vocab.lexemes.at(id_), is_spacy)
+            doc.push_back(self.vocab.lexemes.at(id_), is_spacy)
 
         cdef int length = doc.length
         array = numpy.zeros(shape=(length, len(self.codecs)), dtype=numpy.int)
@@ -139,20 +144,20 @@ cdef class Serializer:
         return doc
 
 
-cdef class AttributeEncoder:
+cdef class CodecWrapper:
     """Wrapper around HuffmanCodec"""
     def __init__(self, freqs, id=0):
         cdef uint64_t key
         cdef uint64_t count
-        cdef pair[uint64_t] item
-        cdef priority_queue[pair[uint64_t]] items
+        cdef pair[uint64_t, uint64_t] item
+        cdef priority_queue[pair[uint64_t, uint64_t]] items
         for key, count in freqs:
             item.first = count
             item.second = key
             items.push(item)
         
-        weights = array('f')
-        keys = array('i')
+        weights = [] #array('f')
+        keys = [] #array('i')
         key_to_i = PreshMap()
         i = 0
         while not items.empty():
@@ -188,8 +193,8 @@ cdef class HuffmanCodec:
 
         eol (uint32_t): The index of the weight of the EOL symbol.
     """
-    def __init__(self, float[:] weights, unt32_t eol):
-        self.codes.resize(len(probs))
+    def __init__(self, float[:] weights, uint32_t eol):
+        self.codes.resize(len(weights))
         for i in range(len(self.codes)):
             self.codes[i].bits = 0
             self.codes[i].length = 0