diff --git a/src/quickfix.c b/src/quickfix.c
index 414fe65..6f7d3a5 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -8011,6 +8011,10 @@
 	    abort = mark_quickfix_ctx(win->w_llist_ref, copyID);
 	    if (abort)
 		return abort;
+
+	    abort = mark_quickfix_user_data(win->w_llist_ref, copyID);
+	    if (abort)
+		return abort;
 	}
     }
 
diff --git a/src/testdir/test_quickfix.vim b/src/testdir/test_quickfix.vim
index 47b9b47..0aa82ef 100644
--- a/src/testdir/test_quickfix.vim
+++ b/src/testdir/test_quickfix.vim
@@ -4208,6 +4208,18 @@
   enew | only
 endfunc
 
+" Similar to the problem above, but for user data.
+func Test_ll_window_user_data()
+  call setloclist(0, [#{bufnr: bufnr(), user_data: {}}])
+  lopen
+  wincmd t
+  close
+  call test_garbagecollect_now()
+  call feedkeys("\<CR>", 'tx')
+  call test_garbagecollect_now()
+  %bwipe!
+endfunc
+
 " The following test used to crash vim
 func Test_lfile_crash()
   sp Xtest
diff --git a/src/version.c b/src/version.c
index 782f431..ba33f43 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    728,
+/**/
     727,
 /**/
     726,