diff --git a/pkgs/tools/security/onlykey/default.nix b/pkgs/tools/security/onlykey/default.nix
index 2ac033ba24b1..4cad7e513acd 100644
--- a/pkgs/tools/security/onlykey/default.nix
+++ b/pkgs/tools/security/onlykey/default.nix
@@ -9,8 +9,18 @@
 }:
 
 let
+  # parse the version from package.json
+  version =
+    let
+      packageJson = builtins.fromJSON (builtins.readFile ./package.json);
+      splits = builtins.split "^.*#v(.*)$" (builtins.getAttr "onlykey" (builtins.head packageJson));
+      matches = builtins.elemAt splits 1;
+      elem = builtins.head matches;
+    in
+    elem;
+
   # this must be updated anytime this package is updated.
-  onlykeyPkg = "onlykey-git://github.com/trustcrypto/OnlyKey-App.git#v5.3.3";
+  onlykeyPkg = "onlykey-git://github.com/trustcrypto/OnlyKey-App.git#v${version}";
 
   # define a shortcut to get to onlykey.
   onlykey = self."${onlykeyPkg}";