diff --git a/doc/lispref/frames.texi b/doc/lispref/frames.texi
index 0ad4f52bfc0..7f14e002892 100644
--- a/doc/lispref/frames.texi
+++ b/doc/lispref/frames.texi
@@ -2808,6 +2808,9 @@ Note that a frame cannot be deleted as long as its minibuffer serves as
 surrogate minibuffer for another frame (@pxref{Minibuffers and Frames}).
 Normally, you cannot delete a frame if all other frames are invisible,
 but if @var{force} is non-@code{nil}, then you are allowed to do so.
+Also, the initial terminal frame of an Emacs process running as daemon
+(@pxref{Initial Options, daemon,, emacs, The GNU Emacs Manual}) can be
+deleted if and only if @var{force} is non-@code{nil}.
 @end deffn
 
 @defun frame-live-p frame
diff --git a/etc/NEWS b/etc/NEWS
index 33b042720b5..13479790407 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -2195,6 +2195,11 @@ The unused variables 'block-comment-start' and 'block-comment-end',
 which never actually had any effect when set by major modes, have been
 removed.
 
++++
+** 'delete-frame' now needs non-nil FORCE argument to delete daemon frame.
+The initial terminal frame of an Emacs process running as daemon can be
+deleted via 'delete-frame' if and only if its optional FORCE argument is
+non-nil.
 
 * Lisp Changes in Emacs 31.1
 
diff --git a/src/frame.c b/src/frame.c
index f2acb19c77d..95fcb9ca7ff 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -2481,6 +2481,8 @@ delete_frame (Lisp_Object frame, Lisp_Object force)
       else
 	error ("Attempt to delete the only frame");
     }
+  else if (IS_DAEMON && FRAME_INITIAL_P (f) && NILP (force))
+    error ("Attempt to delete daemon's initial frame");
 #ifdef HAVE_X_WINDOWS
   else if ((x_dnd_in_progress && f == x_dnd_frame)
 	   || (x_dnd_waiting_for_finish && f == x_dnd_finish_frame))
@@ -2953,10 +2955,11 @@ FRAME must be a live frame and defaults to the selected one.
 When `undelete-frame-mode' is enabled, the 16 most recently deleted
 frames can be undeleted with `undelete-frame', which see.
 
-A frame may not be deleted if its minibuffer serves as surrogate
-minibuffer for another frame.  Normally, you may not delete a frame if
-all other frames are invisible, but if the second optional argument
-FORCE is non-nil, you may do so.
+Do not delete a frame whose minibuffer serves as surrogate minibuffer
+for another frame.  Do not delete a frame if all other frames are
+invisible unless the second optional argument FORCE is non-nil.  Do not
+delete the initial terminal frame of an Emacs process running as daemon
+unless FORCE is non-nil.
 
 This function runs `delete-frame-functions' before actually
 deleting the frame, unless the frame is a tooltip.