diff --git a/flake.nix b/flake.nix
index 1022bb5..0d022b5 100644
--- a/flake.nix
+++ b/flake.nix
@@ -117,7 +117,7 @@
         cargoLock = { 
           lockFile = ./Cargo.lock;
           outputHashes = {
-              "core_io-0.1.888888888" = "sha256-PtKamRQ9RlWeB2f/r5bska3iCoYisJvoPrG9iNvO0ac=";
+              "core_io-0.1.9999" = "sha256-PtKamRQ9RlWeB2f/r5bska3iCoYisJvoPrG9iNvO0ac=";
             };
         };