diff --git a/examples/shell.nix b/examples/shell.nix
index 882fc2f..ff0463c 100644
--- a/examples/shell.nix
+++ b/examples/shell.nix
@@ -3,6 +3,7 @@ let
 in
   import "${nix-bitcoin}/helper/makeShell.nix" {
     configDir = ./.;
+    shellVersion = "0.0.51";
     # Set this to modify your shell
     # extraShellInitCmds = pkgs: ''<my bash code>'';
   }
diff --git a/helper/makeShell.nix b/helper/makeShell.nix
index ab92b68..7a2d1b1 100644
--- a/helper/makeShell.nix
+++ b/helper/makeShell.nix
@@ -1,4 +1,4 @@
-{ configDir, extraShellInitCmds ? (pkgs: "") }:
+{ configDir, shellVersion ? null, extraShellInitCmds ? (pkgs: "") }:
 let
   nixpkgs = (import ../pkgs/nixpkgs-pinned.nix).nixpkgs;
   pkgs = import nixpkgs {};