diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index 3e6acd9b388..58ca19f7fe2 100644
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -4637,13 +4637,14 @@ DESC must be a `package-desc' object."
         vars)
     (dolist-with-progress-reporter (group custom-current-group-alist)
         "Scanning for modified user options..."
-      (dolist (ent (get (cdr group) 'custom-group))
-        (when (and (custom-variable-p (car ent))
-                   (boundp (car ent))
-                   (not (eq (custom--standard-value (car ent))
-                            (default-toplevel-value (car ent))))
-                   (file-in-directory-p (car group) (package-desc-dir desc)))
-          (push (car ent) vars))))
+      (when (and (car group)
+                 (file-in-directory-p (car group) (package-desc-dir desc)))
+        (dolist (ent (get (cdr group) 'custom-group))
+          (when (and (custom-variable-p (car ent))
+                     (boundp (car ent))
+                     (not (eq (custom--standard-value (car ent))
+                              (default-toplevel-value (car ent)))))
+            (push (car ent) vars)))))
     (dlet ((reporter-prompt-for-summary-p t))
       (reporter-submit-bug-report maint name vars))))