diff --git a/benches/bench_main.rs b/benches/bench_main.rs
index 0c1a62c..b2fc5ba 100644
--- a/benches/bench_main.rs
+++ b/benches/bench_main.rs
@@ -1,3 +1,5 @@
+#![cfg_attr(feature = "fail-on-warnings", deny(warnings))]
+
 use {
     criterion::{
         black_box, criterion_group, criterion_main, Bencher, Benchmark, Criterion, Throughput,
@@ -26,7 +28,7 @@ where
 {
     let value: T = rng.gen();
     if value != T::zero() {
-        return value;
+        value
     } else {
         T::one()
     }
diff --git a/build.rs b/build.rs
index 0c34fa6..f54d0f9 100644
--- a/build.rs
+++ b/build.rs
@@ -7,6 +7,7 @@
 
 #![allow(dead_code)]
 #![allow(unused_variables)]
+#![cfg_attr(feature = "fail-on-warnings", deny(warnings))]
 
 use std::env;
 use std::ffi::OsString;