diff --git a/library/compiler-builtins/libm/src/lib.rs b/library/compiler-builtins/libm/src/lib.rs
index f54366b95ae2..06ef4592dcee 100644
--- a/library/compiler-builtins/libm/src/lib.rs
+++ b/library/compiler-builtins/libm/src/lib.rs
@@ -383,7 +383,6 @@ pub trait F64Ext {
     #[cfg(todo)]
     fn ceil(self) -> Self;
 
-    #[cfg(todo)]
     fn round(self) -> Self;
 
     #[cfg(todo)]
@@ -504,7 +503,6 @@ impl F64Ext for f64 {
         ceil(self)
     }
 
-    #[cfg(todo)]
     #[inline]
     fn round(self) -> Self {
         round(self)