diff --git a/prelude/rust/build.bzl b/prelude/rust/build.bzl
index 9294a7a9f4d0..646d22c81871 100644
--- a/prelude/rust/build.bzl
+++ b/prelude/rust/build.bzl
@@ -1352,7 +1352,7 @@ def _rustc_invoke(
 
     toolchain_info = compile_ctx.toolchain_info
 
-    plain_env, path_env = process_env(compile_ctx, ctx.attrs.env, exec_is_windows)
+    plain_env, path_env = process_env(compile_ctx, toolchain_info.rustc_env |ctx.attrs.env, exec_is_windows)
 
     more_plain_env, more_path_env = process_env(compile_ctx, env, exec_is_windows)
     plain_env.update(more_plain_env)
diff --git a/prelude/rust/rust_toolchain.bzl b/prelude/rust/rust_toolchain.bzl
index a69e40d69ae4..48d16d5f29d5 100644
--- a/prelude/rust/rust_toolchain.bzl
+++ b/prelude/rust/rust_toolchain.bzl
@@ -53,6 +53,8 @@ rust_toolchain_attrs = {
     # FIXME(JakobDegen): Can't use `list[str]` here, because then the default is wrong, but can't
     # use a non-empty list as the default because lists are mutable
     "rustc_coverage_flags": provider_field(typing.Any, default = ("-Cinstrument-coverage",)),
+    # Extra env variables that should be made available to the rustc executable.
+    "rustc_env": provider_field(dict[str, typing.Any], default = {}),
     # Extra env variables that should be made available to the rustdoc executable.
     "rustdoc_env": provider_field(dict[str, typing.Any], default = {}),
     # Extra flags for rustdoc invocations