diff --git a/spacy/_ml.py b/spacy/_ml.py
index 5f8ce9470..e60e8a610 100644
--- a/spacy/_ml.py
+++ b/spacy/_ml.py
@@ -346,16 +346,16 @@ def get_token_vectors(tokens_attrs_vectors, drop=0.):
 
 
 def fine_tune(model1, combine=None):
-    def fine_tune_fwd(docs, drop=0.):
+    def fine_tune_fwd(docs_tokvecs, drop=0.):
+        docs, tokvecs = docs_tokvecs
+        lengths = model.ops.asarray([len(doc) for doc in docs], dtype='i')
         X1, bp_X1 = model1.begin_update(docs)
-        lengths = [len(doc) for doc in docs]
-        X2 = model1.ops.flatten(X1)
 
         def fine_tune_bwd(d_output, sgd=None):
-            bp_X1(d_output, sgd=sgd)
+            bp_X1(model1.ops.flatten(d_output), sgd=sgd)
             return d_output
 
-        return (X1+X2, lengths), fine_tune_bwd
+        return model1.ops.unflatten(X1+X2, lengths), fine_tune_bwd
     model = wrap(fine_tune_fwd)
     return model
 
@@ -410,30 +410,21 @@ def preprocess_doc(docs, drop=0.):
 def build_tagger_model(nr_class, token_vector_width, **cfg):
     with Model.define_operators({'>>': chain, '+': add}):
         # Input: (doc, tensor) tuples
-        embed_docs = with_getitem(0, 
+        embed_docs = ( 
             FeatureExtracter([NORM])
+            >> flatten
             >> HashEmbed(token_vector_width, 1000)
-            >> flatten_add_lengths
         )
  
         model = ( 
             fine_tune(embed_docs)
-            >> 
-            with_getitem(0, 
-                FeatureExtracter([NORM])
-                >> HashEmbed(token_vector_width, 1000)
-                >> flatten_add_lengths
-            )
-            >> with_getitem(1,
-                flatten_add_lengths) 
-            >> add_tuples
             >> with_flatten(
                 Maxout(token_vector_width, token_vector_width)
                 >> Softmax(nr_class, token_vector_width)
             )
         )
-        return model
-
+    model.nI = None
+    return model
 
 
 def build_text_classifier(nr_class, width=64, **cfg):
diff --git a/spacy/pipeline.pyx b/spacy/pipeline.pyx
index b96387351..848653c5c 100644
--- a/spacy/pipeline.pyx
+++ b/spacy/pipeline.pyx
@@ -253,23 +253,25 @@ class NeuralTagger(BaseThincComponent):
         self.cfg = dict(cfg)
 
     def __call__(self, doc):
-        tags = self.predict([doc.tensor])
+        tags = self.predict(([doc], [doc.tensor]))
         self.set_annotations([doc], tags)
         return doc
 
     def pipe(self, stream, batch_size=128, n_threads=-1):
         for docs in cytoolz.partition_all(batch_size, stream):
+            docs = list(docs)
             tokvecs = [d.tensor for d in docs]
-            tag_ids = self.predict(tokvecs)
+            tag_ids = self.predict((docs, tokvecs))
             self.set_annotations(docs, tag_ids)
             yield from docs
 
-    def predict(self, tokvecs):
-        scores = self.model(tokvecs)
+    def predict(self, docs_tokvecs):
+        scores = self.model(docs_tokvecs)
         scores = self.model.ops.flatten(scores)
         guesses = scores.argmax(axis=1)
         if not isinstance(guesses, numpy.ndarray):
             guesses = guesses.get()
+        tokvecs = docs_tokvecs[1]
         guesses = self.model.ops.unflatten(guesses,
                     [tv.shape[0] for tv in tokvecs])
         return guesses
@@ -295,7 +297,7 @@ class NeuralTagger(BaseThincComponent):
         if self.model.nI is None:
             self.model.nI = tokvecs[0].shape[1]
 
-        tag_scores, bp_tag_scores = self.model.begin_update(tokvecs, drop=drop)
+        tag_scores, bp_tag_scores = self.model.begin_update(docs_tokvecs, drop=drop)
         loss, d_tag_scores = self.get_loss(docs, golds, tag_scores)
 
         d_tokvecs = bp_tag_scores(d_tag_scores, sgd=sgd)