diff --git a/src/testdir/test_cursor_func.vim b/src/testdir/test_cursor_func.vim
index 2ae7580..b0444d5 100644
--- a/src/testdir/test_cursor_func.vim
+++ b/src/testdir/test_cursor_func.vim
@@ -540,9 +540,28 @@
   call assert_equal(8, virtcol2col(0, 1, 7))
   call assert_equal(8, virtcol2col(0, 1, 8))
 
+  let w = winwidth(0)
+  call setline(2, repeat('a', w + 2))
+  let win_nosbr = win_getid()
+  split
+  setlocal showbreak=!!
+  let win_sbr = win_getid()
+  call assert_equal(w, virtcol2col(win_nosbr, 2, w))
+  call assert_equal(w + 1, virtcol2col(win_nosbr, 2, w + 1))
+  call assert_equal(w + 2, virtcol2col(win_nosbr, 2, w + 2))
+  call assert_equal(w + 2, virtcol2col(win_nosbr, 2, w + 3))
+  call assert_equal(w, virtcol2col(win_sbr, 2, w))
+  call assert_equal(w + 1, virtcol2col(win_sbr, 2, w + 1))
+  call assert_equal(w + 1, virtcol2col(win_sbr, 2, w + 2))
+  call assert_equal(w + 1, virtcol2col(win_sbr, 2, w + 3))
+  call assert_equal(w + 2, virtcol2col(win_sbr, 2, w + 4))
+  call assert_equal(w + 2, virtcol2col(win_sbr, 2, w + 5))
+  close
+
   call assert_fails('echo virtcol2col("0", 1, 20)', 'E1210:')
   call assert_fails('echo virtcol2col(0, "1", 20)', 'E1210:')
   call assert_fails('echo virtcol2col(0, 1, "1")', 'E1210:')
+
   bw!
 endfunc
 
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index e5d56ac..60e9921 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -3514,12 +3514,32 @@
 
 " Test for virtcol()
 func Test_virtcol()
-  enew!
+  new
   call setline(1, "the\tquick\tbrown\tfox")
   norm! 4|
   call assert_equal(8, virtcol('.'))
   call assert_equal(8, virtcol('.', v:false))
   call assert_equal([4, 8], virtcol('.', v:true))
+
+  let w = winwidth(0)
+  call setline(2, repeat('a', w + 2))
+  let win_nosbr = win_getid()
+  split
+  setlocal showbreak=!!
+  let win_sbr = win_getid()
+  call assert_equal([w, w], virtcol([2, w], v:true, win_nosbr))
+  call assert_equal([w + 1, w + 1], virtcol([2, w + 1], v:true, win_nosbr))
+  call assert_equal([w + 2, w + 2], virtcol([2, w + 2], v:true, win_nosbr))
+  call assert_equal([w, w], virtcol([2, w], v:true, win_sbr))
+  call assert_equal([w + 3, w + 3], virtcol([2, w + 1], v:true, win_sbr))
+  call assert_equal([w + 4, w + 4], virtcol([2, w + 2], v:true, win_sbr))
+  close
+
+  call assert_equal(0, virtcol(''))
+  call assert_equal([0, 0], virtcol('', v:true))
+  call assert_equal(0, virtcol('.', v:false, 5001))
+  call assert_equal([0, 0], virtcol('.', v:true, 5001))
+
   bwipe!
 endfunc
 
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index 23a6835..5e57b90 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -4811,6 +4811,9 @@
   v9.CheckDefAndScriptFailure(['virtcol(".", "a")'], [
     'E1013: Argument 2: type mismatch, expected bool but got string',
     'E1212: Bool required for argument 2'])
+  v9.CheckDefAndScriptFailure(['virtcol(".", v:true, [])'], [
+    'E1013: Argument 3: type mismatch, expected number but got list',
+    'E1210: Number required for argument 3'])
   v9.CheckDefExecAndScriptFailure(['virtcol("")'],
     'E1209: Invalid value for a line number')
   new