diff --git a/src/Query.php b/src/Query.php
index 5e58032..3c23e58 100644
--- a/src/Query.php
+++ b/src/Query.php
@@ -90,22 +90,23 @@ protected static function replaceHolder($pdo, $key, $type, $value, &$bind_values
         }
 
         if ($type === '@int') {
+            if (is_int($value)) {
+                return $value;
+            }
+
             if (!is_numeric($value)) {
                 throw new \DomainException(sprintf('param "%s" must be numeric', $key));
             }
 
-            $s = (string)$value;
-            if ($s < self::INT64_MIN || self::INT64_MAX < $s) {
+            if ($value < self::INT64_MIN || self::INT64_MAX < $value) {
                 throw new \DomainException(sprintf('param "%s" is integer out of range.', $key));
             }
 
-            $is_zero = $s === 0 || $s === '0';
-
-            if (!$is_zero && !preg_match('/\A-?[1-9][0-9]*\z/', $s)) {
-                throw new \DomainException();
+            if ($value !== '0' && !preg_match('/\A-?[1-9][0-9]*\z/', $value)) {
+                throw new \DomainException(sprintf('param "%s" is unexpected integer notation.', $key));
             }
 
-            return (int)$s;
+            return (int)$value;
         }
 
         if ($type === '@int[]') {
@@ -128,7 +129,7 @@ protected static function replaceHolder($pdo, $key, $type, $value, &$bind_values
                 throw new \LogicException('Validation Error.');
             }
 
-            if (!preg_match('/\A(?:-?[1-9][0-9]*)(?:,-?[1-9][0-9]*)*\z/', $valuesString)) {
+            if ($value !== '0' && !preg_match('/\A(?:-?[1-9][0-9]*)(?:,-?[1-9][0-9]*)*\z/', $valuesString)) {
                 throw new \DomainException(sprintf('param "%s[%]"'));
             }
 
@@ -168,7 +169,7 @@ protected static function replaceHolder($pdo, $key, $type, $value, &$bind_values
             return $key;
         }
 
-        if ($type === '') {
+        if ($type === '' || $type === '@') {
             throw new \DomainException(sprintf('type specifier for param "%s" not found', $key));
         } else {
             throw new \DomainException(sprintf('unexpected type "%s"', $type));
diff --git a/tests/Query/ReplaceHolderTest.php b/tests/Query/ReplaceHolderTest.php
new file mode 100644
index 0000000..229c2e3
--- /dev/null
+++ b/tests/Query/ReplaceHolderTest.php
@@ -0,0 +1,89 @@
+<?php
+
+namespace Teto\SQL\Query;
+
+use Teto\SQL\Query;
+use Teto\SQL\DummyPDO;
+
+/**
+ * @author    USAMI Kenta <tadsan@zonu.me>
+ * @copyright 2019 USAMI Kenta
+ * @license   https://github.com/BaguettePHP/TetoSQL/blob/master/LICENSE MPL-2.0
+ */
+final class ReplaceHolderTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @dataProvider acceptDataProvider
+     */
+    public function test_accept($type, $input, $expected)
+    {
+        $pdo = new DummyPDO();
+
+        $actual = call_user_func(\Closure::bind(function () use ($pdo, $type, $input) {
+            return Query::replaceHolder($pdo, ':key', "@{$type}", $input, $bind_values);
+        }, null, Query::class));
+
+        $this->assertSame($expected, $actual);
+    }
+
+    public function acceptDataProvider()
+    {
+        return [
+            ['ascdesc', 'ASC', 'ASC'],
+            ['ascdesc', 'DESC', 'DESC'],
+            ['ascdesc', 'asc', 'asc'],
+            ['ascdesc', 'desc', 'desc'],
+            ['int', 1, 1],
+            ['int', '1', 1],
+            ['int', 0, 0],
+            ['int', '0', 0],
+            ['int', '9223372036854775807', 9223372036854775807],
+            ['int', '-9223372036854775808', (int)'-9223372036854775808'],
+            ['int[]', [1, 2, 3], '1,2,3'],
+            ['int[]', ['1', '2', '3'], '1,2,3'],
+            ['int[]',
+             ['9223372036854775807', '-9223372036854775808'],
+             '9223372036854775807,-9223372036854775808',
+            ],
+            ['string', 0, '@0@'],
+            ['string', '0', '@0@'],
+            ['string', '', '@@'],
+            ['string[]', ['', ''], '@@,@@'],
+        ];
+    }
+
+    /**
+     * @dataProvider rejeceptDataProvider
+     */
+    public function test_raise_exception($type, $input, $expected_message)
+    {
+        $pdo = new DummyPDO();
+
+        $this->expectException(\DomainException::class);
+        $this->expectExceptionMessage($expected_message);
+
+        call_user_func(\Closure::bind(function () use ($pdo, $type, $input) {
+            return Query::replaceHolder($pdo, ':key', $type, $input, $bind_values);
+        }, null, Query::class));
+    }
+
+    public function rejeceptDataProvider()
+    {
+        return [
+            ['', null, 'type specifier for param ":key" not found'],
+            ['@', null, 'type specifier for param ":key" not found'],
+            ['@piyo', null, 'unexpected type "@piyo"'],
+            ['@ascdesc', 'foo', 'param ":key" must be "ASC", "DESC", "asc" or "desc"'],
+            ['@int', '-0', 'param ":key" is unexpected integer notation'],
+            ['@int', '9223372036854775808', 'param ":key" is integer out of range.'],
+            ['@int', '-9223372036854775809', 'param ":key" is integer out of range.'],
+            ['@int[]', 0, 'param ":key" must be int array'],
+            ['@int[]', [], 'param ":key" must be not empty int array'],
+            ['@int[]', ['1', 'a', '3'], 'param ":key[]" is integer out of range.'],
+            ['@string', [], 'param ":key" must be string or numeric'],
+            ['@string[]', '', 'param ":key" must be string array'],
+            ['@string[]', [], 'param ":key" must be not empty string array'],
+            ['@string[]', ['', null], 'element of param ":key" must be string or numeric'],
+        ];
+    }
+}
diff --git a/tests/SQLite/QueryTest.php b/tests/SQLite/QueryTest.php
index bfbbc39..b3f74bd 100644
--- a/tests/SQLite/QueryTest.php
+++ b/tests/SQLite/QueryTest.php
@@ -27,7 +27,7 @@ public function setUp()
 
     public function getPDO()
     {
-        if (is_null($this->pdo)) {
+        if ($this->pdo === null) {
             $dsn = 'sqlite:/' . __DIR__ . '/db.sq3';
             $this->pdo = new \PDO($dsn, null, null, [\PDO::ATTR_PERSISTENT => true]);
         }