diff --git a/src/buffer.c b/src/buffer.c
index 0624f9d..697efa3 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2494,6 +2494,7 @@
     clear_string_option(&buf->b_p_cinw);
     clear_string_option(&buf->b_p_cot);
     clear_string_option(&buf->b_p_cpt);
+    clear_string_option(&buf->b_p_ise);
 #ifdef FEAT_COMPL_FUNC
     clear_string_option(&buf->b_p_cfu);
     free_callback(&buf->b_cfu_cb);