diff --git a/src/rtstartup/rsbegin.rs b/src/rtstartup/rsbegin.rs
index d1b6fe6655a..bbabed20ec1 100644
--- a/src/rtstartup/rsbegin.rs
+++ b/src/rtstartup/rsbegin.rs
@@ -23,9 +23,20 @@
 // of other runtime components (registered via yet another special image section).
 
 #![crate_type="rlib"]
-#![no_std]
+#![feature(no_core, lang_items, optin_builtin_traits)]
+#![no_core]
 #![allow(non_camel_case_types)]
 
+#[lang="sized"]
+trait Sized {}
+
+#[lang="copy"]
+trait Copy {}
+
+#[lang="sync"]
+trait Sync {}
+impl Sync for .. {}
+
 #[cfg(all(target_os="windows", target_arch = "x86", target_env="gnu"))]
 pub mod eh_frames
 {
diff --git a/src/rtstartup/rsend.rs b/src/rtstartup/rsend.rs
index 5e4e13ebd05..1ab194d5eb9 100644
--- a/src/rtstartup/rsend.rs
+++ b/src/rtstartup/rsend.rs
@@ -11,7 +11,12 @@
 // See rsbegin.rs for details.
 
 #![crate_type="rlib"]
-#![no_std]
+#![feature(no_core, lang_items, optin_builtin_traits)]
+#![no_core]
+
+#[lang="sync"]
+trait Sync {}
+impl Sync for .. {}
 
 #[cfg(all(target_os="windows", target_arch = "x86", target_env="gnu"))]
 pub mod eh_frames
diff --git a/src/test/run-pass/smallest-hello-world.rs b/src/test/run-pass/smallest-hello-world.rs
index b11970560d5..7fc6e6ba1b0 100644
--- a/src/test/run-pass/smallest-hello-world.rs
+++ b/src/test/run-pass/smallest-hello-world.rs
@@ -22,7 +22,7 @@ extern "rust-intrinsic" { fn transmute<T, U>(t: T) -> U; }
 
 #[lang = "eh_personality"] extern fn eh_personality() {}
 #[lang = "eh_unwind_resume"] extern fn eh_unwind_resume() {}
-#[lang = "panic_fmt"] fn panic_fmt() -> ! { loop {} }
+#[lang = "panic_fmt"] extern fn panic_fmt() -> ! { loop {} }
 #[no_mangle] pub extern fn rust_eh_register_frames () {}
 #[no_mangle] pub extern fn rust_eh_unregister_frames () {}