diff --git a/leim/quail/symbol-ksc.el b/leim/quail/symbol-ksc.el
index 108af45e04d..ad0a758c15d 100644
--- a/leim/quail/symbol-ksc.el
+++ b/leim/quail/symbol-ksc.el
@@ -32,10 +32,10 @@
 (require 'quail)
 
 (defun quail-hangul-switch-back (key idx)
-  (if (not input-method-history
+  (if (not input-method-history)
       (toggle-input-method t)
     (quail-delete-region)
-    (activate-input-method (car input-method-history))
+    (activate-input-method (car input-method-history)))
   (throw 'quail-tag nil))
 
 (quail-define-package