diff --git a/.buildkite/pipeline.yml b/.buildkite/pipeline.yml
index 95c9417..e711ae5 100644
--- a/.buildkite/pipeline.yml
+++ b/.buildkite/pipeline.yml
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2020 Serokell <https://serokell.io/>
+#
+# SPDX-License-Identifier: MPL-2.0
+
 steps:
   - label: Check Nix flake
     commands:
diff --git a/shell.nix b/shell.nix
index 9eb132a..e858b2e 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2020 Serokell <https://serokell.io/>
+#
+# SPDX-License-Identifier: MPL-2.0
+
 (import
   (
     let