diff --git a/src/testdir/test_vimscript.vim b/src/testdir/test_vimscript.vim
index f12d810..89c1001 100644
--- a/src/testdir/test_vimscript.vim
+++ b/src/testdir/test_vimscript.vim
@@ -7083,6 +7083,15 @@
     call assert_fails('let &scrolljump .= "j"', 'E734:')
     set scrolljump&vim
 
+    let &foldlevelstart = 2
+    let &foldlevelstart -= 1
+    call assert_equal(1, &foldlevelstart)
+    let &foldlevelstart -= 1
+    call assert_equal(0, &foldlevelstart)
+    let &foldlevelstart = 2
+    let &foldlevelstart -= 2
+    call assert_equal(0, &foldlevelstart)
+
     " Test for register
     let @/ = 1
     call assert_fails('let @/ += 1', 'E734:')