1 files changed, 4 insertions, 1 deletions
diff --git a/src/nvim/undo.c b/src/nvim/undo.c
index 1f74bada41..df92b2c036 100644
--- a/src/nvim/undo.c
+++ b/src/nvim/undo.c
@@ -2971,7 +2971,10 @@ static char_u *u_save_line(linenr_T lnum)
 bool bufIsChanged(buf_T *buf)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  return !bt_dontwrite(buf) && (buf->b_changed || file_ff_differs(buf, true));
+  // In a "prompt" buffer we do respect 'modified', so that we can control
+  // closing the window by setting or resetting that option.
+  return  (!bt_dontwrite(buf) || bt_prompt(buf))
+    && (buf->b_changed || file_ff_differs(buf, true));
 }
 
 // Return true if any buffer has changes.  Also buffers that are not written.