diff --git a/pkgs/build-support/rust/lib/default.nix b/pkgs/build-support/rust/lib/default.nix
index e492d03e3026..a5769e761294 100644
--- a/pkgs/build-support/rust/lib/default.nix
+++ b/pkgs/build-support/rust/lib/default.nix
@@ -74,7 +74,7 @@
       # pkgsTargetTarget.stdenv.cc is often simply wrong.  We must omit
       # the following lines when rustTargetPlatform collides with
       # rustHostPlatform.
-      + lib.optionalString (rustTargetPlatform != rustHostPlatform) ''
+      + lib.optionalString (stdenv.hostPlatform != stdenv.targetPlatform) ''
         "CC_${stdenv.targetPlatform.rust.cargoEnvVarTarget}=${ccForTarget}" \
         "CXX_${stdenv.targetPlatform.rust.cargoEnvVarTarget}=${cxxForTarget}" \
         "CARGO_TARGET_${stdenv.targetPlatform.rust.cargoEnvVarTarget}_LINKER=${ccForTarget}" \