diff --git a/apex.h b/apex.h
index f2600aa..1d1f34d 100644
--- a/apex.h
+++ b/apex.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Apex kernel-userspace interface definition(s).
  *
diff --git a/apex_driver.c b/apex_driver.c
index 3952567..670ada3 100644
--- a/apex_driver.c
+++ b/apex_driver.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* Driver for the Apex chip.
  *
  * Copyright (C) 2018 Google, Inc.
diff --git a/gasket.h b/gasket.h
index 593d508..c0ea9ad 100644
--- a/gasket.h
+++ b/gasket.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Common Gasket device kernel and user space declarations.
  *
  * Copyright (C) 2018 Google, Inc.
diff --git a/gasket_constants.h b/gasket_constants.h
index b39e3e3..e70c222 100644
--- a/gasket_constants.h
+++ b/gasket_constants.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Copyright (C) 2018 Google, Inc.
  *
  * This software is licensed under the terms of the GNU General Public
diff --git a/gasket_core.c b/gasket_core.c
index 45914eb..a09f491 100644
--- a/gasket_core.c
+++ b/gasket_core.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* Gasket generic driver framework. This file contains the implementation
  * for the Gasket generic driver framework - the functionality that is common
  * across Gasket devices.
diff --git a/gasket_core.h b/gasket_core.h
index 5d6535a..be25d93 100644
--- a/gasket_core.h
+++ b/gasket_core.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Gasket generic driver. Defines the set of data types and functions necessary
  * to define a driver using the Gasket generic driver framework.
  *
diff --git a/gasket_interrupt.c b/gasket_interrupt.c
index d1461b3..28bb80d 100644
--- a/gasket_interrupt.c
+++ b/gasket_interrupt.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* Copyright (C) 2018 Google, Inc.
  *
  * This software is licensed under the terms of the GNU General Public
diff --git a/gasket_interrupt.h b/gasket_interrupt.h
index 3a8afae..2220ca4 100644
--- a/gasket_interrupt.h
+++ b/gasket_interrupt.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Gasket common interrupt module. Defines functions for enabling
  * eventfd-triggered interrupts between a Gasket device and a host process.
diff --git a/gasket_ioctl.c b/gasket_ioctl.c
index 4758083..c5d7bee 100644
--- a/gasket_ioctl.c
+++ b/gasket_ioctl.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* Copyright (C) 2018 Google, Inc.
  *
  * This software is licensed under the terms of the GNU General Public
diff --git a/gasket_ioctl.h b/gasket_ioctl.h
index df86800..457b316 100644
--- a/gasket_ioctl.h
+++ b/gasket_ioctl.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Copyright (C) 2018 Google, Inc.
  *
  * This software is licensed under the terms of the GNU General Public
diff --git a/gasket_logging.h b/gasket_logging.h
index fa17b4a..e288da6 100644
--- a/gasket_logging.h
+++ b/gasket_logging.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Common logging utilities for the Gasket driver framework.
  *
  * Copyright (C) 2018 Google, Inc.
diff --git a/gasket_page_table.c b/gasket_page_table.c
index 5d3d33c..e86c160 100644
--- a/gasket_page_table.c
+++ b/gasket_page_table.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* Implementation of Gasket page table support.
  *
  * Copyright (C) 2018 Google, Inc.
diff --git a/gasket_page_table.h b/gasket_page_table.h
index f2f519a..2074239 100644
--- a/gasket_page_table.h
+++ b/gasket_page_table.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Gasket Page Table functionality. This file describes the address
  * translation/paging functionality supported by the Gasket driver framework.
  * As much as possible, internal details are hidden to simplify use -
diff --git a/gasket_sysfs.c b/gasket_sysfs.c
index a3705d6..b16ecac 100644
--- a/gasket_sysfs.c
+++ b/gasket_sysfs.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* Copyright (C) 2018 Google, Inc.
  *
  * This software is licensed under the terms of the GNU General Public
diff --git a/gasket_sysfs.h b/gasket_sysfs.h
index df9360e..26aa091 100644
--- a/gasket_sysfs.h
+++ b/gasket_sysfs.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Set of common sysfs utilities.
  *
  * Copyright (C) 2018 Google, Inc.