diff --git a/src/flash/nor/fm4.c b/src/flash/nor/fm4.c
index 09865d2ab..2881f1201 100644
--- a/src/flash/nor/fm4.c
+++ b/src/flash/nor/fm4.c
@@ -1,3 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
 /*
  * Spansion FM4 flash
  *
diff --git a/src/jtag/drivers/cmsis_dap.h b/src/jtag/drivers/cmsis_dap.h
index 7c64d492c..cf929b069 100644
--- a/src/jtag/drivers/cmsis_dap.h
+++ b/src/jtag/drivers/cmsis_dap.h
@@ -1,3 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
 #ifndef OPENOCD_JTAG_DRIVERS_CMSIS_DAP_H
 #define OPENOCD_JTAG_DRIVERS_CMSIS_DAP_H
 
diff --git a/src/rtos/linux_header.h b/src/rtos/linux_header.h
index a2b408efd..79199643c 100644
--- a/src/rtos/linux_header.h
+++ b/src/rtos/linux_header.h
@@ -1,3 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
 #ifndef OPENOCD_RTOS_LINUX_HEADER_H
 #define OPENOCD_RTOS_LINUX_HEADER_H
 
diff --git a/src/target/openrisc/jsp_server.h b/src/target/openrisc/jsp_server.h
index e5cfaa8b4..a522fa8da 100644
--- a/src/target/openrisc/jsp_server.h
+++ b/src/target/openrisc/jsp_server.h
@@ -1,3 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
 #ifndef OPENOCD_TARGET_OPENRISC_JSP_SERVER_H
 #define OPENOCD_TARGET_OPENRISC_JSP_SERVER_H