diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index 4a1d68efc99b0f33d65577924a3af7a36b7e6b37..01e618421cc5372ba7dc92e358cb0efe214eb6bc 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -1172,7 +1172,7 @@ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 /// reference is obtained. This is often done via runtime checks.
 ///
 /// Note that while mutating or mutably aliasing the contents of an `& UnsafeCell<T>` is
-/// okay (provided you enforce the invariants some other way); it is still undefined behavior
+/// okay (provided you enforce the invariants some other way), it is still undefined behavior
 /// to have multiple `&mut UnsafeCell<T>` aliases.
 ///
 ///