diff --git a/prelude/rust/build.bzl b/prelude/rust/build.bzl
index bba19e6e61073..ab7ce0bbbe2d7 100644
--- a/prelude/rust/build.bzl
+++ b/prelude/rust/build.bzl
@@ -187,7 +187,7 @@ def generate_rustdoc(
     subdir = common_args.subdir + "-rustdoc"
     output = ctx.actions.declare_output(subdir)
 
-    plain_env, path_env = process_env(compile_ctx, ctx.attrs.env, exec_is_windows)
+    plain_env, path_env = process_env(compile_ctx, toolchain_info.rustdoc_env | ctx.attrs.env, exec_is_windows)
     plain_env["RUSTDOC_BUCK_TARGET"] = cmd_args(str(ctx.label.raw_target()))
 
     rustdoc_cmd = cmd_args(
diff --git a/prelude/rust/rust_toolchain.bzl b/prelude/rust/rust_toolchain.bzl
index b921a5d5c1a85..a69e40d69ae4d 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 rustdoc executable.
+    "rustdoc_env": provider_field(dict[str, typing.Any], default = {}),
     # Extra flags for rustdoc invocations
     "rustdoc_flags": provider_field(list[typing.Any], default = []),
     # When you `buck test` a library, also compile and run example code in its