diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1e91132..3578c8d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file. This projec
 to [Semantic Versioning] (http://semver.org/). For change log format,
 use [Keep a Changelog] (http://keepachangelog.com/).
 
-## [2.0.0-alpha3] - In progress
+## [2.0.0-beta1] - In progress
 
 ### Added
 
@@ -19,6 +19,7 @@ use [Keep a Changelog] (http://keepachangelog.com/).
 
 - Fixed null returned value
 - Fixed returning type of ConfigFunction to mixed
+- Fixed default value returned in `AbstractAdapter`
 
 ## [2.0.0-alpha2] - 2021-03-12
 
diff --git a/src/Adapter/AbstractAdapter.php b/src/Adapter/AbstractAdapter.php
index 176d30a..da33728 100644
--- a/src/Adapter/AbstractAdapter.php
+++ b/src/Adapter/AbstractAdapter.php
@@ -33,7 +33,7 @@ public function __construct(int $priority = 0)
      */
     public function get(string $key = null, mixed $default = null): mixed
     {
-        return b_array_traverse_get($this->configuration, $key);
+        return b_array_traverse_get($this->configuration, $key, $default);
     }
 
     /**
diff --git a/tests/Adapter/ArrayAdapterTest.php b/tests/Adapter/ArrayAdapterTest.php
index ad9ffc0..7ac1987 100644
--- a/tests/Adapter/ArrayAdapterTest.php
+++ b/tests/Adapter/ArrayAdapterTest.php
@@ -37,6 +37,7 @@ public function testLoadArray()
         $this->assertEquals('value', $adapter->get('section.foo'));
         $this->assertEquals('value2', $adapter->get('section.qux'));
         $this->assertEquals(['bar' => 'value3'], $adapter->get('section2'));
+        $this->assertEquals('bar', $adapter->get('foo', 'bar'));
 
         $this->assertFalse($adapter->has('baz'));
         $this->assertTrue($adapter->has('section.foo'));
diff --git a/tests/Adapter/IniAdapterTest.php b/tests/Adapter/IniAdapterTest.php
index 8781ebc..bc15142 100644
--- a/tests/Adapter/IniAdapterTest.php
+++ b/tests/Adapter/IniAdapterTest.php
@@ -37,6 +37,7 @@ public function testLoadString()
         $this->assertEquals('value', $adapter->get('section.foo'));
         $this->assertEquals('value2', $adapter->get('section.qux'));
         $this->assertEquals(['bar' => 'value3'], $adapter->get('section2'));
+        $this->assertEquals('bar', $adapter->get('foo', 'bar'));
     }
 
     public function testLoadStringFailed()
diff --git a/tests/Adapter/JsonAdapterTest.php b/tests/Adapter/JsonAdapterTest.php
index 01988b3..f8e51e7 100644
--- a/tests/Adapter/JsonAdapterTest.php
+++ b/tests/Adapter/JsonAdapterTest.php
@@ -40,6 +40,7 @@ public function testLoadString()
         $this->assertEquals('value', $adapter->get('section.foo'));
         $this->assertEquals('value2', $adapter->get('section.qux'));
         $this->assertEquals(['bar' => 'value3'], $adapter->get('section2'));
+        $this->assertEquals('bar', $adapter->get('foo', 'bar'));
 
         $this->assertFalse($adapter->has('baz'));
         $this->assertTrue($adapter->has('section.foo'));