diff --git a/tests/run-pass/foreign-fn-linkname.rs b/tests/run-pass/foreign-fn-linkname.rs
index 3dd30fd676fd..f2ed67385cdc 100644
--- a/tests/run-pass/foreign-fn-linkname.rs
+++ b/tests/run-pass/foreign-fn-linkname.rs
@@ -10,7 +10,7 @@
 
 //ignore-windows: Uses POSIX APIs
 
-#![feature(libc)]
+#![feature(rustc_private)]
 #![allow(unused_extern_crates)] // rustc bug https://github.com/rust-lang/rust/issues/56098
 
 extern crate libc;
diff --git a/tests/run-pass/regions-mock-trans.rs b/tests/run-pass/regions-mock-trans.rs
index 130eaa288ebe..62931493aa00 100644
--- a/tests/run-pass/regions-mock-trans.rs
+++ b/tests/run-pass/regions-mock-trans.rs
@@ -10,7 +10,7 @@
 
 //ignore-windows: Uses POSIX APIs
 
-#![feature(libc)]
+#![feature(rustc_private)]
 
 #![allow(dead_code)]
 
diff --git a/tests/run-pass/thread-local.rs b/tests/run-pass/thread-local.rs
index 8c20e89ab52d..aeedb7034ce5 100644
--- a/tests/run-pass/thread-local.rs
+++ b/tests/run-pass/thread-local.rs
@@ -1,6 +1,6 @@
 //ignore-windows: Uses POSIX APIs
 
-#![feature(libc)]
+#![feature(rustc_private)]
 extern crate libc;
 
 use std::mem;