diff --git a/src/functions.php b/src/functions.php
index 2fe36af5..d3b34e19 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -463,7 +463,7 @@ function laravel_or_fail($app, ?string $caller = null): Application
     }
 
     if (\is_null($caller)) {
-        $caller = transform(debug_backtrace()[1], function ($debug) {
+        $caller = transform(debug_backtrace()[1] ?? [], function ($debug) {
             if (isset($debug['class']) && isset($debug['function'])) {
                 return \sprintf('%s::%s', $debug['class'], $debug['function']);
             }
@@ -472,5 +472,5 @@ function laravel_or_fail($app, ?string $caller = null): Application
         });
     }
 
-    throw Exceptions\ApplicationNotAvailableException::make($caller ?? debug_backtrace()[1]['function']);
+    throw Exceptions\ApplicationNotAvailableException::make($caller);
 }