diff --git a/spacy/cli/convert.py b/spacy/cli/convert.py
index 847051e3f..e95ffd08b 100644
--- a/spacy/cli/convert.py
+++ b/spacy/cli/convert.py
@@ -7,7 +7,6 @@ from pathlib import Path
 from .converters import conllu2json, iob2json
 from ..util import prints
 
-
 # Converters are matched by file extension. To add a converter, add a new entry
 # to this dict with the file extension mapped to the converter function imported
 # from /converters.
@@ -39,4 +38,5 @@ def convert(_, input_file, output_dir, n_sents, morphology):
     if not file_ext in CONVERTERS:
         prints("Can't find converter for %s" % input_path.parts[-1],
                title="Unknown format", exits=1)
-    CONVERTERS[file_ext](input_path, output_path, n_sents, morphology)
+    CONVERTERS[file_ext](input_path, output_path,
+            n_sents=n_sents, morphology=morphology)
diff --git a/spacy/cli/converters/iob2json.py b/spacy/cli/converters/iob2json.py
index 45393dd80..c2e944c0a 100644
--- a/spacy/cli/converters/iob2json.py
+++ b/spacy/cli/converters/iob2json.py
@@ -3,6 +3,7 @@ from __future__ import unicode_literals
 
 from ...compat import json_dumps, path2str
 from ...util import prints
+from ...gold import iob_to_biluo
 
 
 def iob2json(input_path, output_path, n_sents=10, *a, **k):
@@ -29,9 +30,10 @@ def read_iob(file_):
             continue
         tokens = [t.rsplit('|', 2) for t in line.split()]
         words, pos, iob = zip(*tokens)
+        biluo = iob_to_biluo(iob)
         sentences.append([
             {'orth': w, 'tag': p, 'ner': ent}
-            for (w, p, ent) in zip(words, pos, iob)
+            for (w, p, ent) in zip(words, pos, biluo)
         ])
     sentences = [{'tokens': sent} for sent in sentences]
     paragraphs = [{'sentences': [sent]} for sent in sentences]
diff --git a/spacy/gold.pyx b/spacy/gold.pyx
index 558e4e008..faf135b00 100644
--- a/spacy/gold.pyx
+++ b/spacy/gold.pyx
@@ -306,7 +306,7 @@ def read_json_file(loc, docs_filter=None, limit=None):
                     yield [paragraph.get('raw', None), sents]
 
 
-def _iob_to_biluo(tags):
+def iob_to_biluo(tags):
     out = []
     curr_label = None
     tags = list(tags)