diff --git a/primes/README.md b/primes/README.md
index b5e1d72..7808140 100644
--- a/primes/README.md
+++ b/primes/README.md
@@ -3,7 +3,10 @@
 Find all primes from 0 to 10 000 000.  
 Printing time is not included.
 
+There are probably some issues in the code since this result seems a bit *questionable*
+
 | Language | Time   |
 | ---------| -------|
 | Java     | 1836ms |
-| Javascript | 1778.2ms |
\ No newline at end of file
+| Javascript | 1778.2ms |
+| Rust      | 1818ms |
\ No newline at end of file
diff --git a/primes/javascript/primes.js b/primes/javascript/primes.js
index ad62f5e..dd52a9e 100644
--- a/primes/javascript/primes.js
+++ b/primes/javascript/primes.js
@@ -9,6 +9,8 @@ for (let i = 0; i < 10; i++) {
     times.push(totalTime);
 }
 
+console.assert(primes(10_000_000).length === 664_579);
+
 const average = times.reduce((a, b) => a + b, 0) / times.length;
 console.log(`Average time was ${average}ms`)
 
diff --git a/primes/rust/Cargo.toml b/primes/rust/Cargo.toml
index c4b8881..82bda0b 100644
--- a/primes/rust/Cargo.toml
+++ b/primes/rust/Cargo.toml
@@ -6,4 +6,10 @@ edition = "2018"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
-[dependencies]
\ No newline at end of file
+[dependencies]
+
+[profile.dev]
+opt-level = 3
+
+[profile.release]
+opt-level = 3
\ No newline at end of file
diff --git a/primes/rust/src/main.rs b/primes/rust/src/main.rs
index 6b7ac50..f7bbfc3 100644
--- a/primes/rust/src/main.rs
+++ b/primes/rust/src/main.rs
@@ -3,14 +3,17 @@ use std::time::{SystemTime};
 fn main() {
     let mut times = Vec::new();
 
-    for i in 0..10 {
+    for i in 0..2 {
         println!("Starting run {}", i);
         let start = SystemTime::now();
         let _ = primes(10_000_000);
+
         let time = start.elapsed().unwrap().as_millis();
         times.push(time);
     }
 
+    assert_eq!(primes(10_000_000).len(), 664_579);
+
     let average = times.iter().sum::<u128>() / times.len() as u128;
     println!("Took {}ms on average", average);
 }
@@ -21,22 +24,16 @@ fn primes(max: usize) -> Vec<usize> {
 
     primes_list.push(2);
 
-
     for i in 3..max { //go through all numbers
-        let mut is_prime = true;
         for prime in &primes_list { //test each number
             if *prime > (i as f64).sqrt() as usize {
+                primes_list.push(i);
                 break;
             }
             if i % prime == 0 { //i = test number, j = some known prime
-                is_prime = false;
                 break;
             }
         }
-
-        if is_prime {
-            primes_list.push(i);
-        }
     }
 
     return primes_list;