diff --git a/Makefile b/Makefile
index 30db38e..1e1bc43 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,7 @@
+# Part of KPJOY, Copyright (c) 2026 Scott Duensing, under the MIT License.
+# See LICENSE.md for license information.
+# SPDX-License-Identifier: MIT
+#
 # Makefile -- KPJOY.DRV, built on Linux with Open Watcom v2's 16-bit Windows
 # target (the copy JoeyLib's installer sets up, unless WATCOM names another).
 #
diff --git a/README.md b/README.md
index b747566..f7f1cb0 100644
--- a/README.md
+++ b/README.md
@@ -191,7 +191,9 @@ Not yet done: a real 386 or 486 with an analog stick, a real Y cable,
 
 KPJOY is distributed under the MIT License (`LICENSE.md`): it may be used,
 changed and shipped, alone or with a program, as source or as `kpjoy.drv`,
-as long as the copyright and permission notice go with it.
+as long as the copyright and permission notice go with it. Each source
+file opens with a short header that says so
+(`SPDX-License-Identifier: MIT`).
 
 The driver also carries Open Watcom code (its DLL start-up and C library
 helpers), and Open Watcom's license (the Sybase Open Watcom Public
diff --git a/kpjoy.c b/kpjoy.c
index 018b6ad..4004f93 100644
--- a/kpjoy.c
+++ b/kpjoy.c
@@ -1,3 +1,7 @@
+// Part of KPJOY, Copyright (c) 2026 Scott Duensing, under the MIT License.
+// See LICENSE.md for license information.
+// SPDX-License-Identifier: MIT
+//
 // kpjoy.c -- KPJOY.DRV, a joystick driver for Windows 3.1: the PC game
 // port's two sticks for MMSYSTEM's joystick functions (joyGetPos,
 // joyGetDevCaps and the rest).
diff --git a/kpjoy.lnk b/kpjoy.lnk
index b0306bc..a691797 100644
--- a/kpjoy.lnk
+++ b/kpjoy.lnk
@@ -1,3 +1,7 @@
+# Part of KPJOY, Copyright (c) 2026 Scott Duensing, under the MIT License.
+# See LICENSE.md for license information.
+# SPDX-License-Identifier: MIT
+#
 # kpjoy.lnk -- wlink directives for KPJOY.DRV: a Windows 3.x installable
 # driver (a DLL whose entry point MMSYSTEM looks up is DriverProc), its code
 # and data fixed in memory, as joySetCapture's timer calls in at interrupt