diff --git a/lib/primes/src/lib.rs b/lib/primes/src/lib.rs
index 4c9b6d5..8cfaaef 100644
--- a/lib/primes/src/lib.rs
+++ b/lib/primes/src/lib.rs
@@ -47,6 +47,7 @@ where
             }
         }
         vector.reverse(); // so that self.pop removes the smallest prime
+        debug_assert_eq!(number_of_primes, vector.len());
         Primes { vector, set }
     }
 
@@ -161,10 +162,10 @@ mod test {
         assert_eq!(primes.len(), 664_579);
     }
 
-    //     #[ignore]
-    //     #[test]
-    //     fn test_performance_2() {
-    //         let primes = Primes::get_between(2, 1_000_000_000);
-    //         assert_eq!(primes.len(), 50_847_534);
-    //     }
+    #[ignore]
+    #[test]
+    fn test_performance_2() {
+        let primes = Primes::get_between(2, 1_000_000_000);
+        assert_eq!(primes.len(), 50_847_534);
+    }
 }