diff --git a/src/HybridSession.php b/src/HybridSession.php
index d218d0b..06bcef2 100644
--- a/src/HybridSession.php
+++ b/src/HybridSession.php
@@ -137,11 +137,11 @@ public static function init(string $key = null)
 
         session_set_save_handler($instance, true);
 
-        self::$enabled = true;
+        HybridSession::$enabled = true;
     }
 
     public static function is_enabled(): bool
     {
-        return self::$enabled;
+        return HybridSession::$enabled;
     }
 }
diff --git a/src/Store/DatabaseStore.php b/src/Store/DatabaseStore.php
index c628aab..37aec55 100644
--- a/src/Store/DatabaseStore.php
+++ b/src/Store/DatabaseStore.php
@@ -137,7 +137,7 @@ public function gc(int $maxlifetime): int|false
     public static function binaryDataJsonEncode(string $data): string
     {
         return json_encode([
-            self::class,
+            DatabaseStore::class,
             base64_encode($data ?? '')
         ]);
     }
@@ -156,7 +156,7 @@ public static function binaryDataJsonDecode(string $text): ?string
             return null;
         }
 
-        if (!isset($struct[0]) || !isset($struct[1]) || $struct[0] !== self::class) {
+        if (!isset($struct[0]) || !isset($struct[1]) || $struct[0] !== DatabaseStore::class) {
             return null;
         }
 
@@ -166,8 +166,8 @@ public static function binaryDataJsonDecode(string $text): ?string
     private function encryptSessionID(string $sessionID): string
     {
         if (is_null($this->hashAlgoAvailable)) {
-            $this->hashAlgoAvailable = in_array(self::HASH_ALGO, hash_algos());
+            $this->hashAlgoAvailable = in_array(DatabaseStore::HASH_ALGO, hash_algos());
         }
-        return $this->hashAlgoAvailable ? hash(self::HASH_ALGO, $sessionID) : $sessionID;
+        return $this->hashAlgoAvailable ? hash(DatabaseStore::HASH_ALGO, $sessionID) : $sessionID;
     }
 }
diff --git a/tests/Store/TestCookieStore.php b/tests/Store/TestCookieStore.php
index 6a9150d..bbff97c 100644
--- a/tests/Store/TestCookieStore.php
+++ b/tests/Store/TestCookieStore.php
@@ -18,8 +18,8 @@ class TestCookieStore extends CookieStore implements TestOnly
 
     protected function canWrite(): bool
     {
-        if (self::$override_headers_sent !== null) {
-            return !self::$override_headers_sent;
+        if (TestCookieStore::$override_headers_sent !== null) {
+            return !TestCookieStore::$override_headers_sent;
         }
 
         parent::canWrite();