diff --git a/example/std_example.rs b/example/std_example.rs
index 2f1fba590fd..fcc4ed3aa80 100644
--- a/example/std_example.rs
+++ b/example/std_example.rs
@@ -1,3 +1,5 @@
+#![feature(core_intrinsics)]
+
 use std::io::Write;
 
 fn main() {
@@ -7,5 +9,7 @@ fn main() {
 
     writeln!(stderr, "some {} text", "<unknown>").unwrap();
 
-    std::process::Command::new("true").env("c", "d").spawn();
+    let _ = std::process::Command::new("true").env("c", "d").spawn();
+
+    println!("cargo:rustc-link-lib=z");
 }
diff --git a/src/intrinsics.rs b/src/intrinsics.rs
index 3eaa7c06a76..624a929326b 100644
--- a/src/intrinsics.rs
+++ b/src/intrinsics.rs
@@ -330,7 +330,7 @@ pub fn codegen_intrinsic_call<'a, 'tcx: 'a>(
             ret.write_cvalue(fx, res);
         };
         cttz | cttz_nonzero, <T> (v arg) {
-            let res = CValue::ByVal(fx.bcx.ins().clz(arg), fx.layout_of(T));
+            let res = CValue::ByVal(fx.bcx.ins().ctz(arg), fx.layout_of(T));
             ret.write_cvalue(fx, res);
         };
         ctpop, <T> (v arg) {