diff --git a/ks.c b/ks.c
index 29211cb..5b000c1 100644
--- a/ks.c
+++ b/ks.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: BSD-3-Clause
 #include <sys/types.h>
 #include <assert.h>
 #include <ctype.h>
diff --git a/oscompat.c b/oscompat.c
index d66385e..e4af3ea 100644
--- a/oscompat.c
+++ b/oscompat.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: BSD-3-Clause
 #ifdef _WIN32
 
 #include <stdio.h>
diff --git a/oscompat.h b/oscompat.h
index 883126e..b7730bd 100644
--- a/oscompat.h
+++ b/oscompat.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
 #ifndef __OSCOMPAT_H__
 #define __OSCOMPAT_H__
 
diff --git a/patch.h b/patch.h
index f1374b8..9726303 100644
--- a/patch.h
+++ b/patch.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
 #ifndef __PATCH_H__
 #define __PATCH_H__
 
diff --git a/program.h b/program.h
index 11aa025..773a343 100644
--- a/program.h
+++ b/program.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
 #ifndef __PROGRAM_H__
 #define __PROGRAM_H__
 
diff --git a/qdl.h b/qdl.h
index 4d35ef0..ea13ab8 100644
--- a/qdl.h
+++ b/qdl.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
 #ifndef __QDL_H__
 #define __QDL_H__
 
diff --git a/ramdump.c b/ramdump.c
index 9e9838c..baa87ff 100644
--- a/ramdump.c
+++ b/ramdump.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: BSD-3-Clause
 #include <getopt.h>
 #include <stdbool.h>
 #include <stdio.h>
diff --git a/read.h b/read.h
index a8fce4a..f64b334 100644
--- a/read.h
+++ b/read.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
 #ifndef __READ_H__
 #define __READ_H__
 
diff --git a/usb.c b/usb.c
index 73e77bc..a5e4e6c 100644
--- a/usb.c
+++ b/usb.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: BSD-3-Clause
 #include <sys/types.h>
 #include <fcntl.h>
 #include <stdbool.h>
diff --git a/ux.c b/ux.c
index d91d5a0..236cf02 100644
--- a/ux.c
+++ b/ux.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: BSD-3-Clause
 #include <stdarg.h>
 #ifdef _WIN32
 #include <windows.h>