diff --git a/src/Session.php b/src/Session.php
index 813eb25..4790441 100644
--- a/src/Session.php
+++ b/src/Session.php
@@ -135,8 +135,12 @@ public function start(array $customOptions = []) : bool
             throw new LogicException('Session was already active');
         }
         if ( ! @\session_start($this->getOptions($customOptions))) {
+            $message = '';
+            if (\error_get_last()) {
+                $message = ': ' . \error_get_last()['message'];
+            }
             throw new RuntimeException(
-                'Session could not be started: ' . \error_get_last()['message']
+                'Session could not be started' . $message
             );
         }
         $time = \time();