diff --git a/src/Core/Config/AbstractDbaConfigAdapter.php b/src/Core/Config/AbstractDbaConfigAdapter.php
index c2e8bda5d..bae75122a 100644
--- a/src/Core/Config/AbstractDbaConfigAdapter.php
+++ b/src/Core/Config/AbstractDbaConfigAdapter.php
@@ -2,8 +2,6 @@
 
 namespace Friendica\Core\Config;
 
-use Friendica\Database\DBA;
-
 abstract class AbstractDbaConfigAdapter
 {
 	/** @var bool */
diff --git a/src/Core/Config/ConfigCache.php b/src/Core/Config/ConfigCache.php
index 0c9e1f486..b86ec3860 100644
--- a/src/Core/Config/ConfigCache.php
+++ b/src/Core/Config/ConfigCache.php
@@ -18,7 +18,7 @@ class ConfigCache implements IConfigCache, IPConfigCache
 	 */
 	public function __construct(array $config = [])
 	{
-		$this->config = $config;
+		$this->loadConfigArray($config);
 	}
 
 	/**
@@ -110,6 +110,9 @@ class ConfigCache implements IConfigCache, IPConfigCache
 		} else {
 			if (isset($this->config[$cat][$key])) {
 				unset($this->config[$cat][$key]);
+				if (count($this->config[$cat]) == 0) {
+					unset($this->config[$cat]);
+				}
 			}
 		}
 	}
@@ -160,6 +163,12 @@ class ConfigCache implements IConfigCache, IPConfigCache
 	{
 		if (isset($this->config[$uid][$cat][$key])) {
 			unset($this->config[$uid][$cat][$key]);
+			if (count($this->config[$uid][$cat]) == 0) {
+				unset($this->config[$uid][$cat]);
+				if (count($this->config[$uid]) == 0) {
+					unset($this->config[$uid]);
+				}
+			}
 		}
 	}
 
diff --git a/tests/src/Core/Config/ConfigCacheTest.php b/tests/src/Core/Config/ConfigCacheTest.php
new file mode 100644
index 000000000..25ea6030f
--- /dev/null
+++ b/tests/src/Core/Config/ConfigCacheTest.php
@@ -0,0 +1,175 @@
+<?php
+
+namespace Friendica\Test\Core\Config;
+
+use Friendica\Core\Config\ConfigCache;
+use Friendica\Test\MockedTest;
+
+class ConfigCacheTest extends MockedTest
+{
+	public function dataTests()
+	{
+		return [
+			'normal' => [
+				'data' => [
+					'system' => [
+						'test' => 'it',
+						'boolTrue' => true,
+						'boolFalse' => false,
+						'int' => 235,
+						'dec' => 2.456,
+						'array' => ['1', 2, '3', true, false],
+					],
+					'config' => [
+						'a' => 'value',
+					],
+				]
+			]
+		];
+	}
+
+	private function assertConfigValues($data, ConfigCache $configCache, $uid = null)
+	{
+		foreach ($data as $cat => $values) {
+			foreach ($values as $key => $value) {
+				if (isset($uid)) {
+					$this->assertEquals($data[$cat][$key], $configCache->getP($uid, $cat, $key));
+				} else {
+					$this->assertEquals($data[$cat][$key], $configCache->get($cat, $key));
+				}
+			}
+		}
+	}
+
+	/**
+	 * Test the loadConfigArray() method without override
+	 * @dataProvider dataTests
+	 */
+	public function testLoadConfigArray($data)
+	{
+		$configCache = new ConfigCache();
+		$configCache->loadConfigArray($data);
+
+		$this->assertConfigValues($data, $configCache);
+	}
+
+	/**
+	 * Test the loadConfigArray() method with overrides
+	 * @dataProvider dataTests
+	 */
+	public function testLoadConfigArrayOverride($data)
+	{
+		$override = [
+			'system' => [
+				'test' => 'not',
+				'boolTrue' => false,
+			]
+		];
+
+		$configCache = new ConfigCache();
+		$configCache->loadConfigArray($data);
+		$configCache->loadConfigArray($override);
+
+		$this->assertConfigValues($data, $configCache);
+
+		// override the value
+		$configCache->loadConfigArray($override, true);
+
+		$this->assertEquals($override['system']['test'], $configCache->get('system', 'test'));
+		$this->assertEquals($override['system']['boolTrue'], $configCache->get('system', 'boolTrue'));
+	}
+
+	/**
+	 * Test the getAll() method
+	 * @dataProvider dataTests
+	 */
+	public function testGetAll($data)
+	{
+		$configCache = new ConfigCache();
+		$configCache->loadConfigArray($data);
+
+		$all = $configCache->getAll();
+
+		$this->assertContains($data['system'], $all);
+
+		// config values are stored directly in the array base
+		$this->assertEquals($data['config']['a'], $all['a']);
+	}
+
+	/**
+	 * Test the set() and get() method
+	 * @dataProvider dataTests
+	 */
+	public function testSetGet($data)
+	{
+		$configCache = new ConfigCache();
+
+		foreach ($data as $cat => $values) {
+			foreach ($values as $key => $value) {
+				$configCache->set($cat, $key, $value);
+			}
+		}
+
+		$this->assertConfigValues($data, $configCache);
+	}
+
+	/**
+	 * Test the delete() method
+	 * @dataProvider dataTests
+	 */
+	public function testDelete($data)
+	{
+		$configCache = new ConfigCache($data);
+
+		foreach ($data as $cat => $values) {
+			foreach ($values as $key => $value) {
+				$configCache->delete($cat, $key);
+			}
+		}
+
+		$this->assertEmpty($configCache->getAll());
+	}
+
+	/**
+	 * Test the setP() and getP() methods
+	 * @dataProvider dataTests
+	 */
+	public function testSetGetP($data)
+	{
+		$configCache = new ConfigCache();
+		$uid = 345;
+
+		foreach ($data as $cat => $values) {
+			foreach ($values as $key => $value) {
+				$configCache->setP($uid, $cat, $key, $value);
+			}
+		}
+
+		$this->assertConfigValues($data, $configCache, $uid);
+	}
+
+
+	/**
+	 * Test the deleteP() method
+	 * @dataProvider dataTests
+	 */
+	public function testDeleteP($data)
+	{
+		$configCache = new ConfigCache();
+		$uid = 345;
+
+		foreach ($data as $cat => $values) {
+			foreach ($values as $key => $value) {
+				$configCache->setP($uid, $cat, $key, $value);
+			}
+		}
+
+		foreach ($data as $cat => $values) {
+			foreach ($values as $key => $value) {
+				$configCache->deleteP($uid, $cat, $key);
+			}
+		}
+
+		$this->assertEmpty($configCache->getAll());
+	}
+}