diff --git a/src/libsyntax/ptr.rs b/src/libsyntax/ptr.rs
index bb1744e2df169..3effe53cd29b0 100644
--- a/src/libsyntax/ptr.rs
+++ b/src/libsyntax/ptr.rs
@@ -101,6 +101,7 @@ impl<T: 'static> P<T> {
                 // Recreate self from the raw pointer.
                 Some(P { ptr: Box::from_raw(p) })
             } else {
+                drop(Box::from_raw(p));
                 None
             }
         }