diff --git a/.pre-commit-entry.sh b/.pre-commit-entry.sh
new file mode 100755
index 0000000..3577577
--- /dev/null
+++ b/.pre-commit-entry.sh
@@ -0,0 +1,3 @@
+#! /usr/bin/env sh
+
+nix run github:kamadorueda/alejandra -- -q "$@"
diff --git a/.pre-commit-hooks.yaml b/.pre-commit-hooks.yaml
new file mode 100644
index 0000000..af03c1a
--- /dev/null
+++ b/.pre-commit-hooks.yaml
@@ -0,0 +1,7 @@
+- id: alejandra
+  name: alejandra
+  description: Format Nix code with Alejandra.
+  entry: .pre-commit-entry.sh
+  language: script
+  files: \.nix$
+  minimum_pre_commit_version: 1.18.1