diff --git a/src/testdir/test_gf.vim b/src/testdir/test_gf.vim
index 3d429f3..8317cb5 100644
--- a/src/testdir/test_gf.vim
+++ b/src/testdir/test_gf.vim
@@ -227,6 +227,7 @@
   endfunc
   set includeexpr=s:IncludeFunc()
   call assert_equal(expand('<SID>') .. 'IncludeFunc()', &includeexpr)
+  call assert_equal(expand('<SID>') .. 'IncludeFunc()', &g:includeexpr)
   new | only
   call setline(1, 'TestFile1')
   let g:IncludeFname = ''
@@ -235,11 +236,35 @@
   bw!
   set includeexpr=<SID>IncludeFunc()
   call assert_equal(expand('<SID>') .. 'IncludeFunc()', &includeexpr)
+  call assert_equal(expand('<SID>') .. 'IncludeFunc()', &g:includeexpr)
   new | only
   call setline(1, 'TestFile2')
   let g:IncludeFname = ''
   call assert_fails('normal! gf', 'E447:')
   call assert_equal('TestFile2', g:IncludeFname)
+  bw!
+  setlocal includeexpr=
+  setglobal includeexpr=s:IncludeFunc()
+  call assert_equal(expand('<SID>') .. 'IncludeFunc()', &g:includeexpr)
+  call assert_equal('', &includeexpr)
+  new
+  call assert_equal(expand('<SID>') .. 'IncludeFunc()', &includeexpr)
+  call setline(1, 'TestFile3')
+  let g:IncludeFname = ''
+  call assert_fails('normal! gf', 'E447:')
+  call assert_equal('TestFile3', g:IncludeFname)
+  bw!
+  setlocal includeexpr=
+  setglobal includeexpr=<SID>IncludeFunc()
+  call assert_equal(expand('<SID>') .. 'IncludeFunc()', &g:includeexpr)
+  call assert_equal('', &includeexpr)
+  new
+  call assert_equal(expand('<SID>') .. 'IncludeFunc()', &includeexpr)
+  call setline(1, 'TestFile4')
+  let g:IncludeFname = ''
+  call assert_fails('normal! gf', 'E447:')
+  call assert_equal('TestFile4', g:IncludeFname)
+  bw!
   set includeexpr&
   delfunc s:IncludeFunc
   bw!