diff --git a/shell.nix b/shell.nix
index db48151d2..99c521865 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,7 +1,9 @@
 let
+  lock = builtins.fromJSON (builtins.readFile ./flake.lock);
   shell =
-    (import (fetchTarball "https://github.com/edolstra/flake-compat/archive/master.tar.gz") {
-      src = ./.;
-    }).shellNix;
+    (import (fetchTarball {
+      url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+      sha256 = lock.nodes.flake-compat.locked.narHash;
+    }) { src = ./.; }).shellNix;
 in
 shell.default // shell.devShells.${builtins.currentSystem}