diff --git a/pkgs/build-support/rust/build-rust-package/default.nix b/pkgs/build-support/rust/build-rust-package/default.nix
index db0d2c53bb1e..84700ff29af0 100644
--- a/pkgs/build-support/rust/build-rust-package/default.nix
+++ b/pkgs/build-support/rust/build-rust-package/default.nix
@@ -72,10 +72,6 @@ let
       sha256 = args.cargoSha256;
     } // depsExtraArgs);
 
-  # If we have a cargoSha256 fixed-output derivation, validate it at build time
-  # against the src fixed-output derivation to check consistency.
-  validateCargoDeps = args ? cargoHash || args ? cargoSha256;
-
   target = rust.toRustTargetSpec stdenv.hostPlatform;
   targetIsJSON = lib.hasSuffix ".json" target;
   useSysroot = targetIsJSON && !__internal_dontAddSysroot;