diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index feaa5e4..8c917bc 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -2426,10 +2426,10 @@
   let g:test_is_flaky = 1
 
   let origwin = win_getid()
-  let ptybuf = term_start(&shell, #{hidden: 1})
-  let winid = popup_create(ptybuf, #{minwidth: 40, minheight: 10})
+  let termbuf = term_start(&shell, #{hidden: 1})
+  let winid = popup_create(termbuf, #{minwidth: 40, minheight: 10})
   " Wait for shell to start
-  call WaitForAssert({-> assert_equal("run", job_status(term_getjob(ptybuf)))})
+  call WaitForAssert({-> assert_equal("run", job_status(term_getjob(termbuf)))})
   sleep 100m
   " Check this doesn't crash
   call assert_equal(winnr(), winnr('j'))
@@ -2440,11 +2440,16 @@
   " Cannot quit while job is running
   call assert_fails('call feedkeys("\<C-W>:quit\<CR>", "xt")', 'E948:')
 
-  " Cannot enter Terminal-Normal mode.
+  " Cannot enter Terminal-Normal mode. (TODO: but it works...)
   call feedkeys("xxx\<C-W>N", 'xt')
   call assert_fails('call feedkeys("gf", "xt")', 'E863:')
   call feedkeys("a\<C-U>", 'xt')
 
+  " Cannot open a second one.
+  let termbuf2 = term_start(&shell, #{hidden: 1})
+  call assert_fails('call popup_create(termbuf2, #{})', 'E861:')
+  call term_sendkeys(termbuf2, "exit\<CR>")
+
   " Exiting shell closes popup window
   call feedkeys("exit\<CR>", 'xt')
   " Wait for shell to exit
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index ab1961a..7f85f6c 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -2587,9 +2587,8 @@
   let buf1 = term_start(&shell, #{hidden: 1})
   let win1 = popup_create(buf1, {})
   let buf2 = term_start(&shell, #{hidden: 1})
-  let win2 = popup_create(buf2, {})
+  call assert_fails('call popup_create(buf2, {})', 'E861:')
   call popup_close(win1)
-  call popup_close(win2)
   exe buf1 .. 'bwipe!'
   exe buf2 .. 'bwipe!'
 endfunc
@@ -2619,10 +2618,8 @@
   CheckExecutable sh
 
   set hidden
-  let g:buf0 = term_start('sh', #{hidden: 1})
+  let g:buf0 = term_start('sh', #{hidden: 1, term_finish: 'close'})
   call popup_create(g:buf0, {})
-  let g:buf1 = term_start('sh', #{hidden: 1, term_finish: 'close'})
-  call popup_create(g:buf1, {})
   call assert_fails("call term_start(['sh', '-c'], #{curwin: 1})", 'E863:')
 
   call popup_clear(1)