diff --git a/src/libstd/nil.rs b/src/libstd/nil.rs
index 81b7662e58168..360db9608b689 100644
--- a/src/libstd/nil.rs
+++ b/src/libstd/nil.rs
@@ -55,7 +55,9 @@ impl TotalEq for () {
 
 #[cfg(not(test))]
 impl Zero for () {
+    #[inline]
     fn zero() -> () { () }
+    #[inline]
     fn is_zero(&self) -> bool { true }
 }