diff --git a/src/basic/MurmurHash2.c b/src/basic/MurmurHash2.c
index 5859af0a81..43a89a0820 100644
--- a/src/basic/MurmurHash2.c
+++ b/src/basic/MurmurHash2.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: LicenseRef-murmurhash2-public-domain */
 //-----------------------------------------------------------------------------
 // MurmurHash2 was written by Austin Appleby, and is placed in the public
 // domain. The author hereby disclaims copyright to this source code.
diff --git a/src/basic/MurmurHash2.h b/src/basic/MurmurHash2.h
index 1aef3afba0..5758b86039 100644
--- a/src/basic/MurmurHash2.h
+++ b/src/basic/MurmurHash2.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: LicenseRef-murmurhash2-public-domain */
 //-----------------------------------------------------------------------------
 // MurmurHash2 was written by Austin Appleby, and is placed in the public
 // domain. The author hereby disclaims copyright to this source code.
diff --git a/src/boot/efi/crc32.c b/src/boot/efi/crc32.c
index 46b9aeea90..5dfd3db265 100644
--- a/src/boot/efi/crc32.c
+++ b/src/boot/efi/crc32.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: LicenseRef-crc32-no-restriction */
 /* This is copied from util-linux, which in turn copied in the version from Gary S. Brown */
 
 /*
diff --git a/src/boot/efi/crc32.h b/src/boot/efi/crc32.h
index 64150ee948..3af543b84e 100644
--- a/src/boot/efi/crc32.h
+++ b/src/boot/efi/crc32.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-2.1+ */
+/* SPDX-License-Identifier: LicenseRef-crc32-no-restriction */
 #pragma once
 
 #include <efi.h>
diff --git a/src/journal/lookup3.c b/src/journal/lookup3.c
index 74c80b724d..39967f21cd 100644
--- a/src/journal/lookup3.c
+++ b/src/journal/lookup3.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: LicenseRef-lookup3-public-domain */
 /* Slightly modified by Lennart Poettering, to avoid name clashes, and
  * unexport a few functions. */
 
diff --git a/src/journal/lookup3.h b/src/journal/lookup3.h
index 0a01269e43..04e493e95e 100644
--- a/src/journal/lookup3.h
+++ b/src/journal/lookup3.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: LicenseRef-lookup3-public-domain */
 #pragma once
 
 #include <inttypes.h>