diff --git a/src/nvim/eval/buffer.c b/src/nvim/eval/buffer.c
index dd731d0d26..b9070eb0dc 100644
--- a/src/nvim/eval/buffer.c
+++ b/src/nvim/eval/buffer.c
@@ -20,6 +20,7 @@
 #include "nvim/eval/typval_defs.h"
 #include "nvim/eval/window.h"
 #include "nvim/ex_cmds.h"
+#include "nvim/extmark.h"
 #include "nvim/globals.h"
 #include "nvim/macros_defs.h"
 #include "nvim/memline.h"
@@ -790,6 +791,7 @@ void f_prompt_setprompt(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       // If for some odd reason the old prompt is missing,
       // replace prompt line with new-prompt (discards user-input).
       ml_replace_buf(buf, prompt_lno, (char *)new_prompt, true, false);
+      extmark_splice_cols(buf, prompt_lno - 1, 0, old_line_len, new_prompt_len, kExtmarkUndo);
       cursor_col = new_prompt_len;
     } else {
       // Replace prev-prompt + user-input with new-prompt + user-input
@@ -797,6 +799,8 @@ void f_prompt_setprompt(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       if (ml_replace_buf(buf, prompt_lno, new_line, false, false) != OK) {
         xfree(new_line);
       }
+      extmark_splice_cols(buf, prompt_lno - 1, 0, buf->b_prompt_start.mark.col, new_prompt_len,
+                          kExtmarkUndo);
       cursor_col += new_prompt_len - old_prompt_len;
     }
 
diff --git a/test/functional/api/extmark_spec.lua b/test/functional/api/extmark_spec.lua
index 42f3a8fe30..65a1f9ccd3 100644
--- a/test/functional/api/extmark_spec.lua
+++ b/test/functional/api/extmark_spec.lua
@@ -11,7 +11,9 @@ local feed = n.feed
 local clear = n.clear
 local command = n.command
 local exec = n.exec
+local exec_lua = n.exec_lua
 local api = n.api
+local fn = n.fn
 local assert_alive = n.assert_alive
 
 local function expect(contents)
@@ -1562,10 +1564,45 @@ describe('API/extmarks', function()
 
   it('in prompt buffer', function()
     feed('dd')
-    local id = set_extmark(ns, marks[1], 0, 0, {})
+    set_extmark(ns, marks[1], 0, 0, {})
     api.nvim_set_option_value('buftype', 'prompt', {})
     feed('i<esc>')
-    eq({ { id, 0, 2 } }, get_extmarks(ns, 0, -1))
+    eq({ { marks[1], 0, 2 } }, get_extmarks(ns, 0, -1))
+    fn.prompt_setprompt('', 'foo > ')
+    eq({ { marks[1], 0, 6 } }, get_extmarks(ns, 0, -1))
+    feed('ihello')
+    eq({ { marks[1], 0, 11 } }, get_extmarks(ns, 0, -1))
+
+    local function get_extmark_range(id)
+      local rv = get_extmark_by_id(ns, id, { details = true })
+      return rv[3].invalid and 'invalid' or { rv[1], rv[2], rv[3].end_row, rv[3].end_col }
+    end
+
+    set_extmark(ns, marks[2], 0, 0, { invalidate = true, end_col = 6 })
+    set_extmark(ns, marks[3], 0, 6, { invalidate = true, end_col = 11 })
+    set_extmark(ns, marks[4], 0, 0, { invalidate = true, end_col = 11 })
+    set_extmark(ns, marks[5], 0, 0, { invalidate = true, end_row = 1 })
+    fn.prompt_setprompt('', 'floob > ')
+    eq({ 0, 13 }, get_extmark_range(marks[1]))
+    eq('invalid', get_extmark_range(marks[2])) -- extmark spanning old prompt invalidated
+    eq({ 0, 8, 0, 13 }, get_extmark_range(marks[3]))
+    eq({ 0, 8, 0, 13 }, get_extmark_range(marks[4]))
+    eq({ 0, 8, 1, 0 }, get_extmark_range(marks[5]))
+
+    set_extmark(ns, marks[2], 0, 0, { invalidate = true, end_col = 8 })
+    set_extmark(ns, marks[3], 0, 8, { invalidate = true, end_col = 13 })
+    set_extmark(ns, marks[4], 0, 0, { invalidate = true, end_col = 13 })
+    set_extmark(ns, marks[5], 0, 0, { invalidate = true, end_row = 1 })
+    -- Do this in the same event.
+    exec_lua(function()
+      vim.fn.setpos("':", { 0, 1, 999, 0 })
+      vim.fn.prompt_setprompt('', 'discard > ')
+    end)
+    eq({ 0, 10 }, get_extmark_range(marks[1]))
+    eq('invalid', get_extmark_range(marks[2])) -- all spans on line invalidated
+    eq('invalid', get_extmark_range(marks[3]))
+    eq('invalid', get_extmark_range(marks[4]))
+    eq({ 0, 10, 1, 0 }, get_extmark_range(marks[5]))
   end)
 
   it('can get details', function()
diff --git a/test/functional/lua/buffer_updates_spec.lua b/test/functional/lua/buffer_updates_spec.lua
index 6c142cd01e..e884499a98 100644
--- a/test/functional/lua/buffer_updates_spec.lua
+++ b/test/functional/lua/buffer_updates_spec.lua
@@ -1618,6 +1618,40 @@ describe('lua: nvim_buf_attach on_bytes', function()
         { 'test1', 'bytes', 1, 6, 2, 0, 6, 0, 0, 0, 1, 0, 1 },
         { 'test1', 'bytes', 1, 7, 2, 0, 6, 0, 0, 0, 0, 2, 2 },
       }
+      fn.prompt_setprompt('', 'foo > ')
+      check_events {
+        { 'test1', 'bytes', 1, 8, 2, 0, 6, 0, 2, 2, 0, 6, 6 },
+      }
+      feed('hello')
+      check_events {
+        { 'test1', 'bytes', 1, 9, 2, 6, 12, 0, 0, 0, 0, 5, 5 },
+      }
+      fn.prompt_setprompt('', 'uber-foo > ')
+      check_events {
+        { 'test1', 'bytes', 1, 10, 2, 0, 6, 0, 6, 6, 0, 11, 11 },
+      }
+      eq({ '% ', '% ', 'uber-foo > hello' }, api.nvim_buf_get_lines(0, 0, -1, true))
+      -- Do this in the same event.
+      exec_lua(function()
+        vim.fn.setpos("':", { 0, vim.fn.line('.'), 999, 0 })
+        vim.fn.prompt_setprompt('', 'discard > ')
+      end)
+      check_events {
+        { 'test1', 'bytes', 1, 11, 2, 0, 6, 0, 16, 16, 0, 10, 10 },
+      }
+      eq({ '% ', '% ', 'discard > ' }, api.nvim_buf_get_lines(0, 0, -1, true))
+      feed('sup<S-CR>dood')
+      check_events {
+        { 'test1', 'bytes', 1, 12, 2, 10, 16, 0, 0, 0, 0, 3, 3 },
+        { 'test1', 'bytes', 1, 13, 2, 13, 19, 0, 0, 0, 1, 0, 1 },
+        { 'test1', 'bytes', 1, 14, 3, 0, 20, 0, 0, 0, 0, 4, 4 },
+      }
+      eq({ '% ', '% ', 'discard > sup', 'dood' }, api.nvim_buf_get_lines(0, 0, -1, true))
+      fn.prompt_setprompt('', 'cool > ')
+      check_events {
+        { 'test1', 'bytes', 1, 15, 2, 0, 6, 0, 10, 10, 0, 7, 7 },
+      }
+      eq({ '% ', '% ', 'cool > sup', 'dood' }, api.nvim_buf_get_lines(0, 0, -1, true))
     end)
 
     local function test_lockmarks(mode)