diff --git a/gbizinfo_lod/command.py b/gbizinfo_lod/command.py
index 2bbd39c..49f3e43 100644
--- a/gbizinfo_lod/command.py
+++ b/gbizinfo_lod/command.py
@@ -1,4 +1,5 @@
 import csv
+import gzip
 import os
 import shutil
 import time
@@ -127,11 +128,18 @@ MAPPER_TYPES = [
 @click.option(
     "--format",
     "-f",
+    "_format",
     type=click.Choice([v.name for v in RDFFormatType]),
     default=RDFFormatType.nq.name,
 )
+@click.option("--compress", "-c", is_flag=True)
 def convert(
-    work_dir: str, mappers: list[str], processes: int, output_dir: str, format: str
+    work_dir: str,
+    mappers: list[str],
+    processes: int,
+    output_dir: str,
+    _format: str,
+    compress: bool,
 ):
     if not mappers:
         mappers = MAPPER_TYPES
@@ -175,11 +183,15 @@ def convert(
             case _:
                 raise NotImplementedError
 
-        output_file = os.path.join(output_dir, f"{m}.{format}")
+        output_file = os.path.join(
+            output_dir, f"{m}.{_format}" + (".gz" if compress else "")
+        )
         click.echo(f"output: {output_file}")
         click.echo(f"Running {m} mapper ...")
-        with open(output_file, "w") as f:
-            mapper.run(n_jobs=processes, output=f, format=RDFFormatType[format])
+
+        f = gzip.open(output_file, "wt") if compress else open(output_file, "w")
+        mapper.run(n_jobs=processes, output=f, format=RDFFormatType[_format])
+        f.close()
 
 
 @cli.command(help="Fetch CSV data from OutputCSV endpoint")
diff --git a/gbizinfo_lod/mappers/__init__.py b/gbizinfo_lod/mappers/__init__.py
index d8c49f2..41925d7 100644
--- a/gbizinfo_lod/mappers/__init__.py
+++ b/gbizinfo_lod/mappers/__init__.py
@@ -1,16 +1,17 @@
 import csv
 import sys
 from abc import ABC, abstractmethod
-from typing import IO, Iterator, Tuple, Union
 from enum import Enum
+from typing import IO, Iterator, Tuple, Union
 
 from joblib import Parallel, delayed
-from rdflib import BNode, URIRef
+from rdflib import BNode
 from rdflib import Literal as LiteralRdflib
+from rdflib import URIRef
 from rdflib.graph import _ObjectType, _PredicateType, _SubjectType, _TripleType
 from rdflib.namespace import RDF
-from rdflib.plugins.serializers.nt import _nt_row
 from rdflib.plugins.serializers.nquads import _nq_row
+from rdflib.plugins.serializers.nt import _nt_row
 
 _TripleMapType = Tuple[
     _SubjectType, _PredicateType, Union[str, _ObjectType, "BlankPredicateObjectMap"]
diff --git a/gbizinfo_lod/mappers/chotatsu.py b/gbizinfo_lod/mappers/chotatsu.py
index af103cc..9666f95 100644
--- a/gbizinfo_lod/mappers/chotatsu.py
+++ b/gbizinfo_lod/mappers/chotatsu.py
@@ -1,4 +1,5 @@
 from rdflib import URIRef
+
 from ..namespace import *
 from . import _TripleMapType
 from ._katsudo import GbizInfoKatsudoMapper