diff --git a/.clang-tidy b/.clang-tidy
index b40e588a1..8056d7a88 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -1,2 +1,4 @@
+# SPDX-License-Identifier: CC0-1.0
+
 Checks:		-clang-diagnostic-c99-designator
 FormatStyle:	file
diff --git a/src/android/data/nautilus/camera_hal.yaml b/src/android/data/nautilus/camera_hal.yaml
index faddd29ed..2105fcca8 100644
--- a/src/android/data/nautilus/camera_hal.yaml
+++ b/src/android/data/nautilus/camera_hal.yaml
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 cameras:
   "\\_SB_.PCI0.I2C2.CAM0":
     location: back
diff --git a/src/android/data/soraka/camera_hal.yaml b/src/android/data/soraka/camera_hal.yaml
index 2e9964035..d886af06c 100644
--- a/src/android/data/soraka/camera_hal.yaml
+++ b/src/android/data/soraka/camera_hal.yaml
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 cameras:
   "\\_SB_.PCI0.I2C4.CAM1":
     location: front
diff --git a/src/py/meson.build b/src/py/meson.build
index 4ce9668ca..a4586b4ae 100644
--- a/src/py/meson.build
+++ b/src/py/meson.build
@@ -1 +1,3 @@
+# SPDX-License-Identifier: CC0-1.0
+
 subdir('libcamera')
diff --git a/subprojects/.gitignore b/subprojects/.gitignore
index fd3f4a5bf..0a8fd3a67 100644
--- a/subprojects/.gitignore
+++ b/subprojects/.gitignore
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 /googletest-release*
 /libyaml
 /libyuv
diff --git a/subprojects/gtest.wrap b/subprojects/gtest.wrap
index 40128b35d..8892e1842 100644
--- a/subprojects/gtest.wrap
+++ b/subprojects/gtest.wrap
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 [wrap-file]
 directory = googletest-release-1.11.0
 source_url = https://github.com/google/googletest/archive/release-1.11.0.zip
diff --git a/subprojects/libyaml.wrap b/subprojects/libyaml.wrap
index 3d7d0a328..392416c61 100644
--- a/subprojects/libyaml.wrap
+++ b/subprojects/libyaml.wrap
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 [wrap-git]
 directory = libyaml
 url = https://github.com/yaml/libyaml
diff --git a/subprojects/libyuv.wrap b/subprojects/libyuv.wrap
index 8ba51fa00..3417e73f3 100644
--- a/subprojects/libyuv.wrap
+++ b/subprojects/libyuv.wrap
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 [wrap-git]
 directory = libyuv
 url = https://chromium.googlesource.com/libyuv/libyuv.git
diff --git a/subprojects/pybind11.wrap b/subprojects/pybind11.wrap
index e8037a5df..dd02687b5 100644
--- a/subprojects/pybind11.wrap
+++ b/subprojects/pybind11.wrap
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 [wrap-git]
 url = https://github.com/pybind/pybind11.git
 # This is the head of 'smart_holder' branch