diff --git a/src/rustc/rustc.rs b/src/rustc/rustc.rs
index 9fa33f911a168..a888838ce432c 100644
--- a/src/rustc/rustc.rs
+++ b/src/rustc/rustc.rs
@@ -13,6 +13,7 @@
 
 // Set the stack size at link time on Windows. See rustc_driver::in_rustc_thread
 // for the rationale.
+#[allow(unused_attributes)]
 #[cfg_attr(all(windows, target_env = "msvc"), link_args = "/STACK:16777216")]
 // We only build for msvc and gnu now, but we use a exhaustive condition here
 // so we can expect either the stack size to be set or the build fails.
diff --git a/src/tools/rustdoc/main.rs b/src/tools/rustdoc/main.rs
index e726dea84f103..7aca765cead8c 100644
--- a/src/tools/rustdoc/main.rs
+++ b/src/tools/rustdoc/main.rs
@@ -9,6 +9,8 @@
 // except according to those terms.
 
 #![feature(link_args)]
+
+#[allow(unused_attributes)]
 // Set the stack size at link time on Windows. See rustc_driver::in_rustc_thread
 // for the rationale.
 #[cfg_attr(all(windows, target_env = "msvc"), link_args = "/STACK:16777216")]