diff --git a/src/libcore/send_map.rs b/src/libcore/send_map.rs
index 2a010ee4712..53dcff2e315 100644
--- a/src/libcore/send_map.rs
+++ b/src/libcore/send_map.rs
@@ -4,6 +4,10 @@ Sendable hash maps.  Very much a work in progress.
 
 */
 
+// NB: transitionary, de-mode-ing.
+#[forbid(deprecated_mode)];
+#[forbid(deprecated_pattern)];
+
 use cmp::Eq;
 use hash::Hash;
 use to_bytes::IterBytes;
diff --git a/src/libcore/uniq.rs b/src/libcore/uniq.rs
index 1a752ce0e6c..1d5dd8eca87 100644
--- a/src/libcore/uniq.rs
+++ b/src/libcore/uniq.rs
@@ -1,5 +1,9 @@
 //! Operations on unique pointer types
 
+// NB: transitionary, de-mode-ing.
+#[forbid(deprecated_mode)];
+#[forbid(deprecated_pattern)];
+
 use cmp::{Eq, Ord};
 
 impl<T:Eq> ~const T : Eq {
diff --git a/src/libcore/unit.rs b/src/libcore/unit.rs
index 4ccdf12b500..923b0811b3a 100644
--- a/src/libcore/unit.rs
+++ b/src/libcore/unit.rs
@@ -4,6 +4,10 @@ Functions for the unit type.
 
 */
 
+// NB: transitionary, de-mode-ing.
+#[forbid(deprecated_mode)];
+#[forbid(deprecated_pattern)];
+
 use cmp::{Eq, Ord};
 
 impl () : Eq {