diff --git a/.envrc b/.envrc
new file mode 100644
index 00000000..3550a30f
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/.gitignore b/.gitignore
index 750baebf..5b3a622e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
+/.direnv/
 result
 result-*
diff --git a/docs/src/development_environment.md b/docs/src/development_environment.md
index 16367199..b90637db 100644
--- a/docs/src/development_environment.md
+++ b/docs/src/development_environment.md
@@ -5,3 +5,10 @@ To enter the developer shell, run:
 ```console
 nix develop
 ```
+
+To automatically enter the developer shell upon entering the project directory
+with [`direnv`](https://direnv.net), run:
+
+```console
+direnv allow
+```