diff --git a/phpinspect-autoload.el b/phpinspect-autoload.el
index 1b5730e..49f0d5b 100644
--- a/phpinspect-autoload.el
+++ b/phpinspect-autoload.el
@@ -139,12 +139,13 @@ bareword typenames."))
          (prefix (phpinspect-psr4-prefix strat))
          type-fqn)
     (dolist (dir (phpinspect-psr4-directories strat))
-      (dolist (file (phpinspect-fs-directory-files-recursively fs dir "\\.php$"))
-        (setq type-fqn (phpinspect-filename-to-typename dir file prefix))
-        (phpinspect-autoloader-put-type-bag al type-fqn)
-        (puthash type-fqn file typehash)
-        (when own
-          (puthash type-fqn file own-typehash))))))
+      (when (phpinspect-fs-file-directory-p fs dir)
+        (dolist (file (phpinspect-fs-directory-files-recursively fs dir "\\.php$"))
+          (setq type-fqn (phpinspect-filename-to-typename dir file prefix))
+          (phpinspect-autoloader-put-type-bag al type-fqn)
+          (puthash type-fqn file typehash)
+          (when own
+            (puthash type-fqn file own-typehash)))))))
 
 (cl-defmethod phpinspect-al-strategy-execute ((strat phpinspect-psr0))
   (let* ((fs (phpinspect-psr0-fs strat))