diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index 7881c101f9f..3061ab8ee53 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -103,7 +103,6 @@
 #![feature(inplace_iteration)]
 #![feature(lang_items)]
 #![feature(layout_for_ptr)]
-#![feature(libc)]
 #![feature(map_first_last)]
 #![feature(map_into_keys_values)]
 #![feature(maybe_uninit_ref)]
diff --git a/library/panic_abort/src/lib.rs b/library/panic_abort/src/lib.rs
index 3b08a64b22d..7a5c613688d 100644
--- a/library/panic_abort/src/lib.rs
+++ b/library/panic_abort/src/lib.rs
@@ -12,7 +12,6 @@
 #![panic_runtime]
 #![allow(unused_features)]
 #![feature(core_intrinsics)]
-#![feature(libc)]
 #![feature(nll)]
 #![feature(panic_runtime)]
 #![feature(staged_api)]
diff --git a/library/panic_unwind/src/lib.rs b/library/panic_unwind/src/lib.rs
index 6f31e6dcae7..0a193f7bf41 100644
--- a/library/panic_unwind/src/lib.rs
+++ b/library/panic_unwind/src/lib.rs
@@ -19,7 +19,6 @@
 )]
 #![feature(core_intrinsics)]
 #![feature(lang_items)]
-#![feature(libc)]
 #![feature(nll)]
 #![feature(panic_unwind)]
 #![feature(staged_api)]
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index b834361b750..34230629fb0 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -268,7 +268,6 @@
 #![feature(integer_atomics)]
 #![feature(into_future)]
 #![feature(lang_items)]
-#![feature(libc)]
 #![feature(link_args)]
 #![feature(linkage)]
 #![feature(llvm_asm)]