diff --git a/spacy/gold/converters/__init__.py b/spacy/gold/converters/__init__.py
index e44ad407d..a046466fc 100644
--- a/spacy/gold/converters/__init__.py
+++ b/spacy/gold/converters/__init__.py
@@ -1,4 +1,4 @@
-from .conllu2json import conllu2json  # noqa: F401
-from .iob2json import iob2docs # noqa: F401
-from .conll_ner2json import conll_ner2json  # noqa: F401
-from .jsonl2docs import ner_jsonl2json  # noqa: F401
+from .conllu2docs import conllu2docs  # noqa: F401
+from .iob2docs import iob2docs # noqa: F401
+from .conll_ner2docs import conll_ner2docs  # noqa: F401
+from .jsonl2docs import ner_jsonl2docs  # noqa: F401
diff --git a/spacy/gold/converters/conll_ner2json.py b/spacy/gold/converters/conll_ner2doc.py
similarity index 100%
rename from spacy/gold/converters/conll_ner2json.py
rename to spacy/gold/converters/conll_ner2doc.py
diff --git a/spacy/gold/converters/iob2json.py b/spacy/gold/converters/iob2doc.py
similarity index 100%
rename from spacy/gold/converters/iob2json.py
rename to spacy/gold/converters/iob2doc.py
diff --git a/spacy/gold/converters/jsonl2json.py b/spacy/gold/converters/jsonl2docs.py
similarity index 100%
rename from spacy/gold/converters/jsonl2json.py
rename to spacy/gold/converters/jsonl2docs.py
diff --git a/spacy/gold/converters/util.py b/spacy/gold/converters/util.py
new file mode 100644
index 000000000..ed9c84203
--- /dev/null
+++ b/spacy/gold/converters/util.py
@@ -0,0 +1,5 @@
+def merge_sentences(docs, n_sents):
+    merged = []
+    for group in minibatch(docs, size=n_sents):
+        raise NotImplementedError
+    return merged