diff --git a/src/buffer.c b/src/buffer.c
index 4eaf3db..d686467 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1978,6 +1978,9 @@
 #endif
     buf->b_p_ar = -1;
     buf->b_p_ul = NO_LOCAL_UNDOLEVEL;
+#ifdef FEAT_LISP
+    clear_string_option(&buf->b_p_lw);
+#endif
 }
 
 /*