diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index f31f8fec55..14d230331a 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -152,6 +152,8 @@ typedef struct cmdpreview_buf_info {
   buf_T *buf;
   OptInt save_b_p_ul;
   int save_b_changed;
+  pos_T save_b_op_start;
+  pos_T save_b_op_end;
   varnumber_T save_changedtick;
   CpUndoInfo undo_info;
 } CpBufInfo;
@@ -2360,6 +2362,8 @@ static void cmdpreview_prepare(CpInfo *cpinfo)
       cp_bufinfo.buf = buf;
       cp_bufinfo.save_b_p_ul = buf->b_p_ul;
       cp_bufinfo.save_b_changed = buf->b_changed;
+      cp_bufinfo.save_b_op_start = buf->b_op_start;
+      cp_bufinfo.save_b_op_end = buf->b_op_end;
       cp_bufinfo.save_changedtick = buf_get_changedtick(buf);
       cmdpreview_save_undo(&cp_bufinfo.undo_info, buf);
       kv_push(cpinfo->buf_info, cp_bufinfo);
@@ -2438,6 +2442,9 @@ static void cmdpreview_restore_state(CpInfo *cpinfo)
     u_blockfree(buf);
     cmdpreview_restore_undo(&cp_bufinfo.undo_info, buf);
 
+    buf->b_op_start = cp_bufinfo.save_b_op_start;
+    buf->b_op_end = cp_bufinfo.save_b_op_end;
+
     if (cp_bufinfo.save_changedtick != buf_get_changedtick(buf)) {
       buf_set_changedtick(buf, cp_bufinfo.save_changedtick);
     }
diff --git a/test/functional/ui/inccommand_spec.lua b/test/functional/ui/inccommand_spec.lua
index 3ee67a710c..ae6d0e6487 100644
--- a/test/functional/ui/inccommand_spec.lua
+++ b/test/functional/ui/inccommand_spec.lua
@@ -8,6 +8,7 @@ local feed_command = helpers.feed_command
 local expect = helpers.expect
 local feed = helpers.feed
 local insert = helpers.insert
+local funcs = helpers.funcs
 local meths = helpers.meths
 local neq = helpers.neq
 local ok = helpers.ok
@@ -153,6 +154,29 @@ describe(":substitute, 'inccommand' preserves", function()
     ]])
   end)
 
+  it("'[ and '] marks #26439", function()
+    local screen = Screen.new(30, 10)
+    common_setup(screen, 'nosplit', ('abc\ndef\n'):rep(50))
+
+    feed('ggyG')
+    local X = meths.get_vvar('maxcol')
+    eq({0, 1, 1, 0}, funcs.getpos("'["))
+    eq({0, 101, X, 0}, funcs.getpos("']"))
+
+    feed(":'[,']s/def/")
+    poke_eventloop()
+    eq({0, 1, 1, 0}, funcs.getpos("'["))
+    eq({0, 101, X, 0}, funcs.getpos("']"))
+
+    feed('DEF/g')
+    poke_eventloop()
+    eq({0, 1, 1, 0}, funcs.getpos("'["))
+    eq({0, 101, X, 0}, funcs.getpos("']"))
+
+    feed('<CR>')
+    expect(('abc\nDEF\n'):rep(50))
+  end)
+
   for _, case in pairs{"", "split", "nosplit"} do
     it("various delimiters (inccommand="..case..")", function()
       insert(default_text)