diff --git a/src/eval.c b/src/eval.c
index e6175f6..242a1f8 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -6007,6 +6007,7 @@
 
 /*
  * Allocate a list item.
+ * It is not initialized, don't forget to set v_lock.
  */
     listitem_T *
 listitem_alloc()
@@ -18713,6 +18714,7 @@
 		goto errret;
 	    }
 	    li->li_tv.v_type = VAR_STRING;
+	    li->li_tv.v_lock = 0;
 	    li->li_tv.vval.v_string = s;
 	    list_append(list, li);
 	}
diff --git a/src/version.c b/src/version.c
index 5cb09f8..f0107fa 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    597,
+/**/
     596,
 /**/
     595,