diff --git a/src/libstd/base64.rs b/src/libstd/base64.rs
index 1dd8454976d..d0552c64c99 100644
--- a/src/libstd/base64.rs
+++ b/src/libstd/base64.rs
@@ -1,3 +1,5 @@
+#[forbid(deprecated_mode)];
+#[forbid(deprecated_pattern)];
 #[deny(non_camel_case_types)];
 import io::Reader;