diff --git a/src/StorageDirectories.php b/src/StorageDirectories.php
index 4df6d58..753cc38 100644
--- a/src/StorageDirectories.php
+++ b/src/StorageDirectories.php
@@ -26,6 +26,7 @@ public static function create()
             self::Path . '/bootstrap/cache',
             self::Path . '/framework/cache',
             self::Path . '/framework/views',
+            self::Path . '/psysh',
         ];
 
         $directories = array_filter($directories, static fn ($directory) => ! is_dir($directory));
diff --git a/src/bref-init.php b/src/bref-init.php
index 173a467..5a87031 100644
--- a/src/bref-init.php
+++ b/src/bref-init.php
@@ -15,6 +15,11 @@
 
     MaintenanceMode::setUp();
 
+    // Move the location of the PsySH config cache to `/tmp` (because it is writable)
+    $xdgHome = StorageDirectories::Path . '/psysh';
+    $_SERVER['XDG_CONFIG_HOME'] = $_ENV['XDG_CONFIG_HOME'] = $xdgHome;
+    putenv("XDG_CONFIG_HOME=$xdgHome");
+
     $defaultConfigCachePath = $_SERVER['LAMBDA_TASK_ROOT'] . '/bootstrap/cache/config.php';
 
     if (file_exists($defaultConfigCachePath)) {