diff --git a/spacy/morphology.pxd b/spacy/morphology.pxd
index ad9d61eab..aa45c47f0 100644
--- a/spacy/morphology.pxd
+++ b/spacy/morphology.pxd
@@ -35,7 +35,7 @@ cdef class Morphology:
 
     cdef int assign_tag(self, TokenC* token, tag) except -1
 
-    cdef int _assign_tag_id(self, TokenC* token, int tag_id) except -1
+    cdef int assign_tag_id(self, TokenC* token, int tag_id) except -1
     
     cdef int assign_feature(self, uint64_t* morph, feature, value) except -1
 
diff --git a/spacy/morphology.pyx b/spacy/morphology.pyx
index ef546e4e6..e5e5e013f 100644
--- a/spacy/morphology.pyx
+++ b/spacy/morphology.pyx
@@ -39,9 +39,9 @@ cdef class Morphology:
             tag_id = self.reverse_index[self.strings[tag]]
         else:
             tag_id = self.reverse_index[tag]
-        self._assign_tag_id(token, tag_id)
+        self.assign_tag_id(token, tag_id)
 
-    cdef int _assign_tag_id(self, TokenC* token, int tag_id) except -1:
+    cdef int assign_tag_id(self, TokenC* token, int tag_id) except -1:
         if tag_id >= self.n_tags:
             raise ValueError("Unknown tag ID: %s" % tag_id)
         # TODO: It's pretty arbitrary to put this logic here. I guess the justification
diff --git a/spacy/tagger.pyx b/spacy/tagger.pyx
index a387ccb12..53e648f24 100644
--- a/spacy/tagger.pyx
+++ b/spacy/tagger.pyx
@@ -196,7 +196,7 @@ cdef class Tagger:
                 self.model.set_scoresC(eg.c.scores,
                     eg.c.features, eg.c.nr_feat)
                 guess = VecVec.arg_max_if_true(eg.c.scores, eg.c.is_valid, eg.c.nr_class)
-                self.vocab.morphology.assign_tag(&tokens.c[i], guess)
+                self.vocab.morphology.assign_tag_id(&tokens.c[i], guess)
                 eg.fill_scores(0, eg.c.nr_class)
         tokens.is_tagged = True
         tokens._py_tokens = [None] * tokens.length
diff --git a/spacy/tokens/doc.pyx b/spacy/tokens/doc.pyx
index 1200a0517..3d09b7ad0 100644
--- a/spacy/tokens/doc.pyx
+++ b/spacy/tokens/doc.pyx
@@ -577,8 +577,7 @@ cdef class Doc:
             elif attr_id == TAG:
                 for i in range(length):
                     if values[i] != 0:
-                        self.vocab.morphology.assign_tag(&tokens[i],
-                            self.vocab.morphology.reverse_index[values[i]])
+                        self.vocab.morphology.assign_tag(&tokens[i], values[i])
             elif attr_id == POS:
                 for i in range(length):
                     tokens[i].pos = <univ_pos_t>values[i]