diff --git a/tests/ui/foreign/foreign-fn-linkname.rs b/tests/ui/foreign/foreign-fn-linkname.rs
index 47edf6fc7bba..7ced34e73fa7 100644
--- a/tests/ui/foreign/foreign-fn-linkname.rs
+++ b/tests/ui/foreign/foreign-fn-linkname.rs
@@ -1,20 +1,14 @@
 //@ run-pass
 //@ ignore-sgx no libc
 
-// Ensure no false positive on "unused extern crate" lint
-#![deny(unused_extern_crates)]
-
-#![feature(rustc_private)]
-
-extern crate libc;
 use std::ffi::CString;
 
 mod mlibc {
-    use libc::{c_char, size_t};
+    use std::ffi::c_char;
 
     extern "C" {
         #[link_name = "strlen"]
-        pub fn my_strlen(str: *const c_char) -> size_t;
+        pub fn my_strlen(str: *const c_char) -> usize;
     }
 }
 
diff --git a/tests/ui/foreign/foreign2.rs b/tests/ui/foreign/foreign2.rs
index 765f2833f3ce..178a04255cce 100644
--- a/tests/ui/foreign/foreign2.rs
+++ b/tests/ui/foreign/foreign2.rs
@@ -15,7 +15,7 @@ mod zed {
 #[cfg(not(windows))]
 mod mlibc {
     extern crate libc;
-    use libc::{c_int, c_void, size_t, ssize_t};
+    use self::libc::{c_int, c_void, size_t, ssize_t};
 
     extern "C" {
         pub fn write(fd: c_int, buf: *const c_void, count: size_t) -> ssize_t;