diff --git a/application/Utils.php b/application/Utils.php
old mode 100644
new mode 100755
index fa18f158..cb03f11c
--- a/application/Utils.php
+++ b/application/Utils.php
@@ -156,7 +156,7 @@ function is_session_id_valid($sessionId)
         return false;
     }
 
-    if (!preg_match('/^[a-z0-9]{2,32}$/', $sessionId)) {
+    if (!preg_match('/^[a-z0-9]{2,32}$/i', $sessionId)) {
         return false;
     }
 
diff --git a/tests/UtilsTest.php b/tests/UtilsTest.php
old mode 100644
new mode 100755
index e39ce6be..5175dde0
--- a/tests/UtilsTest.php
+++ b/tests/UtilsTest.php
@@ -156,7 +156,7 @@ public function testCheckSupportedPHPVersion52()
      */
     public function testIsSessionIdValid()
     {
-        $this->assertTrue(is_session_id_valid('123456789012345678901234567890az'));
+        $this->assertTrue(is_session_id_valid('azertyuiop123456789AZERTYUIOP1aA'));
     }
 
     /**