diff --git a/src/libcore/tests/lib.rs b/src/libcore/tests/lib.rs
index a3d294e77d3bd..ae12eb116b5c3 100644
--- a/src/libcore/tests/lib.rs
+++ b/src/libcore/tests/lib.rs
@@ -26,7 +26,6 @@
 #![feature(test)]
 #![feature(trusted_len)]
 #![feature(try_trait)]
-#![feature(align_offset)]
 #![feature(reverse_bits)]
 #![feature(inner_deref)]
 #![feature(slice_internals)]
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 7b0e090fb1bf4..215f1bbc971af 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -227,7 +227,6 @@
 // std is implemented with unstable features, many of which are internal
 // compiler details that will never be stable
 // NB: the following list is sorted to minimize merge conflicts.
-#![feature(align_offset)]
 #![feature(alloc_error_handler)]
 #![feature(alloc_layout_extra)]
 #![feature(allocator_api)]