diff --git a/examples/rayon-monte-carlo.rs b/examples/rayon-monte-carlo.rs
index 041f7379c4..f0e7114a65 100755
--- a/examples/rayon-monte-carlo.rs
+++ b/examples/rayon-monte-carlo.rs
@@ -55,8 +55,8 @@ fn main() {
         .into_par_iter()
         .map(|i| {
             let mut rng = ChaCha8Rng::seed_from_u64(SEED);
-            // We chose ChaCha because it's fast, has suitable statical properties for simulation,
-            // and because it supports this set_stream() api, which lets us chose a different stream
+            // We chose ChaCha because it's fast, has suitable statistical properties for simulation,
+            // and because it supports this set_stream() api, which lets us choose a different stream
             // per work item. ChaCha supports 2^64 independent streams.
             rng.set_stream(i);
             let mut count = 0;
@@ -69,7 +69,10 @@ fn main() {
             }
             count
         })
-        .reduce(|| 0usize, |a, b| a + b);
+        .sum::<usize>();
+
+    // assert this is deterministic
+    assert_eq!(in_circle, 7852263);
 
     // prints something close to 3.14159...
     println!(