diff --git a/tests/Dotenv/ValidatorBooleanTest.php b/tests/Dotenv/ValidatorBooleanTest.php
index 6896df62..5a4c875a 100644
--- a/tests/Dotenv/ValidatorBooleanTest.php
+++ b/tests/Dotenv/ValidatorBooleanTest.php
@@ -84,7 +84,7 @@ public function invalidBooleanValuesDataProvider()
 
     /**
      * @dataProvider invalidBooleanValuesDataProvider
-     * @expectedException Dotenv\Exception\ValidationException
+     * @expectedException \Dotenv\Exception\ValidationException
      * @expectedExceptionMessage One or more environment variables failed assertions: INVALID_
      */
     public function testCanInvalidateNonBooleans($boolean)
diff --git a/tests/Dotenv/ValidatorIntegerTest.php b/tests/Dotenv/ValidatorIntegerTest.php
new file mode 100644
index 00000000..77b8eac9
--- /dev/null
+++ b/tests/Dotenv/ValidatorIntegerTest.php
@@ -0,0 +1,81 @@
+<?php
+
+use Dotenv\Dotenv;
+use PHPUnit\Framework\TestCase;
+
+class ValidatorIntegerTest extends TestCase
+{
+    /**
+     * @var string
+     */
+    private $fixturesFolder;
+
+    public function setUp()
+    {
+        $this->fixturesFolder = dirname(__DIR__).'/fixtures/env';
+    }
+
+    /**
+     * List of valid integer values in fixtures/env/integers.env.
+     *
+     * @return array
+     */
+    public function validIntegerValuesDataProvider()
+    {
+        return [
+            ['VALID_ZERO'],
+            ['VALID_ONE'],
+            ['VALID_TWO'],
+
+            ['VALID_LARGE'],
+            ['VALID_HUGE'],
+        ];
+    }
+
+    /**
+     * @dataProvider validIntegerValuesDataProvider
+     */
+    public function testCanValidateIntegers($integer)
+    {
+        $dotenv = Dotenv::create($this->fixturesFolder, 'integers.env');
+        $dotenv->load();
+
+        $dotenv->required($integer)->isInteger();
+
+        $this->assertTrue(true); // anything wrong - an exception will be thrown
+    }
+
+    /**
+     * List of non-integer values in fixtures/env/integers.env.
+     *
+     * @return array
+     */
+    public function invalidIntegerValuesDataProvider()
+    {
+        return [
+            ['INVALID_SOMETHING'],
+            ['INVALID_EMPTY'],
+            ['INVALID_EMPTY_STRING'],
+            ['INVALID_NULL'],
+            ['INVALID_NEGATIVE'],
+            ['INVALID_MINUS'],
+            ['INVALID_TILDA'],
+            ['INVALID_EXCLAMATION'],
+            ['INVALID_SPACES'],
+            ['INVALID_COMMAS'],
+        ];
+    }
+
+    /**
+     * @dataProvider invalidIntegerValuesDataProvider
+     * @expectedException \Dotenv\Exception\ValidationException
+     * @expectedExceptionMessage One or more environment variables failed assertions: INVALID_
+     */
+    public function testCanInvalidateNonIntegers($integer)
+    {
+        $dotenv = Dotenv::create($this->fixturesFolder, 'integers.env');
+        $dotenv->load();
+
+        $dotenv->required($integer)->isInteger();
+    }
+}
diff --git a/tests/fixtures/env/integers.env b/tests/fixtures/env/integers.env
new file mode 100644
index 00000000..4895efc7
--- /dev/null
+++ b/tests/fixtures/env/integers.env
@@ -0,0 +1,17 @@
+VALID_ZERO=0
+VALID_ONE=1
+VALID_TWO=2
+
+VALID_LARGE=99999999
+VALID_HUGE=99999999999999999999999999999999
+
+INVALID_SOMETHING=something
+INVALID_EMPTY=
+INVALID_EMPTY_STRING=""
+INVALID_NULL=null
+INVALID_NEGATIVE=-2
+INVALID_MINUS=-
+INVALID_TILDA=~
+INVALID_EXCLAMATION=!
+INVALID_SPACES=" 123"
+INVALID_COMMAS="123,123"