diff --git a/requirements/requirements.txt b/requirements/requirements.txt
index cd5d3b9..c332afd 100644
--- a/requirements/requirements.txt
+++ b/requirements/requirements.txt
@@ -1,4 +1,4 @@
 click
-DataProperty>=0.7.2
+DataProperty>=0.8.1
 path.py
-SimpleSQLite>=0.4.2
+SimpleSQLite>=0.4.6
diff --git a/setup.py b/setup.py
index 39b4fee..13df3b1 100644
--- a/setup.py
+++ b/setup.py
@@ -1,4 +1,3 @@
-from __future__ import with_statement
 import os.path
 import setuptools
 import sys
diff --git a/sqlitebiter/__init__.py b/sqlitebiter/__init__.py
index ab1bdd5..f3737e0 100644
--- a/sqlitebiter/__init__.py
+++ b/sqlitebiter/__init__.py
@@ -1 +1 @@
-VERSION = "0.1.4"
+VERSION = "0.1.5"
diff --git a/sqlitebiter/_counter.py b/sqlitebiter/_counter.py
new file mode 100644
index 0000000..0fd2595
--- /dev/null
+++ b/sqlitebiter/_counter.py
@@ -0,0 +1,29 @@
+# encoding: utf-8
+
+"""
+.. codeauthor:: Tsuyoshi Hombashi <gogogo.vm@gmail.com>
+"""
+
+from __future__ import absolute_import
+
+
+class ResultCounter(object):
+
+    def __init__(self):
+        self.__success_count = 0
+        self.__fail_count = 0
+
+    def inc_success(self):
+        self.__success_count += 1
+
+    def inc_fail(self):
+        self.__fail_count += 1
+
+    def get_return_code(self):
+        if self.__success_count > 0:
+            return 0
+
+        if self.__fail_count > 0:
+            return 1
+
+        return 2
diff --git a/sqlitebiter/sqlitebiter.py b/sqlitebiter/sqlitebiter.py
index cb1f615..cf76c86 100644
--- a/sqlitebiter/sqlitebiter.py
+++ b/sqlitebiter/sqlitebiter.py
@@ -1,15 +1,14 @@
 #!/usr/bin/env python
 # encoding: utf-8
 
-
 """
 .. codeauthor:: Tsuyoshi Hombashi <gogogo.vm@gmail.com>
 """
 
-
 from __future__ import absolute_import
 import collections
 import re
+import sys
 
 import click
 import dataproperty
@@ -18,6 +17,8 @@
 from simplesqlite.loader import ValidationError
 from simplesqlite.loader import InvalidDataError
 
+from ._counter import ResultCounter
+
 
 CONTEXT_SETTINGS = dict(help_option_names=["-h", "--help"])
 
@@ -81,8 +82,8 @@ def file(files, output_path):
     """
 
     con = create_database(output_path)
+    result_counter = ResultCounter()
 
-    convert_count = 0
     for file_path in files:
         if not path.Path(file_path).isfile():
             continue
@@ -96,12 +97,17 @@ def file(files, output_path):
             for tabledata in loader.load():
                 click.echo("convert '{:s}' to '{:s}' table".format(
                     file_path, tabledata.table_name))
-                con.create_table_from_tabledata(tabledata)
-            convert_count += 1
-        except (ValueError, ValidationError, InvalidDataError):
-            continue
 
-    return 0 if convert_count == 0 else 1
+                try:
+                    con.create_table_from_tabledata(tabledata)
+                    result_counter.inc_success()
+                except (ValueError, IOError):
+                    result_counter.inc_fail()
+                    continue
+        except (ValidationError, InvalidDataError):
+            result_counter.inc_fail()
+
+    sys.exit(result_counter.get_return_code())
 
 
 @cmd.command()
@@ -121,17 +127,26 @@ def gs(credentials, title, output_path):
     """
 
     con = create_database(output_path)
+    result_counter = ResultCounter()
 
     loader = simplesqlite.loader.GoogleSheetsTableLoader()
     loader.source = credentials
     loader.title = title
 
-    for tabledata in loader.load():
-        click.echo("convert '{:s}' to '{:s}' table".format(
-            title, tabledata.table_name))
-        con.create_table_from_tabledata(tabledata)
+    try:
+        for tabledata in loader.load():
+            click.echo("convert '{:s}' to '{:s}' table".format(
+                title, tabledata.table_name))
+
+            try:
+                con.create_table_from_tabledata(tabledata)
+                result_counter.inc_success()
+            except (ValidationError, InvalidDataError):
+                result_counter.inc_fail()
+    except (ValidationError, InvalidDataError):
+        result_counter.inc_fail()
 
-    return 0
+    sys.exit(result_counter.get_return_code())
 
 
 if __name__ == '__main__':
diff --git a/test/test_counter.py b/test/test_counter.py
new file mode 100644
index 0000000..a33a9aa
--- /dev/null
+++ b/test/test_counter.py
@@ -0,0 +1,29 @@
+# encoding: utf-8
+
+"""
+.. codeauthor:: Tsuyoshi Hombashi <gogogo.vm@gmail.com>
+"""
+
+
+import pytest
+from sqlitebiter._counter import ResultCounter
+
+
+class Test_ResultCounter(object):
+
+    @pytest.mark.parametrize(["success", "fail", "expected"], [
+        [0, 0, 2],
+        [1, 0, 0],
+        [1, 1, 0],
+        [0, 1, 1],
+    ])
+    def test_normal(self, success, fail, expected):
+        result_counter = ResultCounter()
+
+        for _i in range(success):
+            result_counter.inc_success()
+
+        for _i in range(fail):
+            result_counter.inc_fail()
+
+        assert result_counter.get_return_code() == expected