diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index fdd9ac4..ea2ee3b 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -2690,7 +2690,7 @@
   split
   wincmd b
   assert_equal(2, winnr())
-  let buf = term_start(&shell, #{hidden: 1})
+  var buf = term_start(&shell, #{hidden: 1})
   popup_create(buf, {})
   TermWait(buf, 100)
   popup_clear(true)