diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index 20b92b294fe..61d764c05c7 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -129,7 +129,8 @@ pub unsafe fn setup(_build: &mut crate::Build) {}
     /* Extra values not defined in the built-in targets yet, but used in std */
     (Some(Mode::Std), "target_env", Some(&["libnx"])),
     // (Some(Mode::Std), "target_os", Some(&[])),
-    (Some(Mode::Std), "target_arch", Some(&["asmjs", "spirv", "nvptx", "xtensa"])),
+    // #[cfg(bootstrap)] loongarch64
+    (Some(Mode::Std), "target_arch", Some(&["asmjs", "spirv", "nvptx", "xtensa", "loongarch64"])),
     /* Extra names used by dependencies */
     // FIXME: Used by serde_json, but we should not be triggering on external dependencies.
     (Some(Mode::Rustc), "no_btreemap_remove_entry", None),