diff --git a/.circleci/config.yml b/.circleci/config.yml
index ebf3d464bd75a0a577a5cecdafd8da8038f3b3f3..d4cc7832347f8acf5605ce0f160db374e8113a11 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -157,7 +157,7 @@ jobs:
 
       - save_cache:
           name: "Cache Nix Store Paths"
-          key: paymentserver-nix-store-v1-{{ .Environment.NIXPKGS_REV }}
+          key: paymentserver-nix-store-v1-{{ checksum "nixpkgs.rev" }}-{{ checksum "ristretto.nix" }}
           paths:
             - "/nix"