diff --git a/src/main.rs b/src/main.rs
index 75ebab2..1788b81 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,11 +4,14 @@
 #![allow(clippy::match_overlapping_arm)]
 #![allow(clippy::new_without_default)]
 
-use std::io::Write;
-
 pub mod solutions;
 pub mod utils;
 
+#[cfg(test)]
+mod tests;
+
+use std::io::Write;
+
 /// Execute the solution (if available) of the specified problem. Also measure
 /// its running time.
 ///
diff --git a/src/tests.rs b/src/tests.rs
new file mode 100644
index 0000000..4e38097
--- /dev/null
+++ b/src/tests.rs
@@ -0,0 +1,98 @@
+use crate::utils;
+use std::io::BufRead;
+
+#[cfg(target_pointer_width = "64")]
+#[test]
+fn is_prime_smaller_test() {
+    let num_of_primes = (0..2i64.pow(32)).filter(|&num| utils::is_prime(num)).count();
+    assert_eq!(num_of_primes, 203280221);
+}
+
+#[cfg(target_pointer_width = "64")]
+#[test]
+fn is_prime_small_test() {
+    let num_of_primes = (2i64.pow(32)..2i64.pow(33)).filter(|&num| utils::is_prime(num)).count();
+    assert_eq!(num_of_primes, 190335585);
+}
+
+#[test]
+fn is_prime_large_test() {
+    let fhandle = std::fs::File::open("res/is_prime_large_test.txt").unwrap();
+    let reader = std::io::BufReader::new(fhandle);
+    for line in reader.lines() {
+        let line = line.unwrap();
+        let mut num_primality = line.split_ascii_whitespace();
+        let num = num_primality.next().unwrap().parse().unwrap();
+        let primality = num_primality.next().unwrap().parse().unwrap();
+        assert_eq!(utils::is_prime(num), primality);
+    }
+}
+
+#[test]
+fn gcd_test() {
+    let fhandle = std::fs::File::open("res/gcd_test.txt").unwrap();
+    let reader = std::io::BufReader::new(fhandle);
+    for line in reader.lines() {
+        let line = line.unwrap();
+        let [a, b, g]: [i64; 3] = line
+            .split_ascii_whitespace()
+            .map(|s| s.parse().unwrap())
+            .collect::<Vec<i64>>()
+            .try_into()
+            .unwrap();
+        assert_eq!(a, utils::gcd(a, a));
+        assert_eq!(b, utils::gcd(b, b));
+        assert_eq!(g, utils::gcd(g, g));
+        assert_eq!(g, utils::gcd(a, b));
+        assert_eq!(g, utils::gcd(b, a));
+    }
+}
+
+#[test]
+fn isqrt_test() {
+    assert_eq!(utils::isqrt(2i64.pow(53) - 1), 94906265);
+    assert_eq!(utils::isqrt(2i64.pow(54) - 1), 134217727);
+}
+
+#[test]
+fn long_test() {
+    let mut num = &utils::Long::new("43").pow(37) * &utils::Long::from(745683);
+    num += &utils::Long::factorial(51);
+    assert_eq!(
+        num.to_string(),
+        "3597031455246992664728898500113748859466269359952342048214143659169"
+    );
+}
+
+#[test]
+fn sieve_of_atkin_smaller_test() {
+    let num_of_primes = utils::SieveOfAtkin::new(2usize.pow(14)).iter().count();
+    assert_eq!(num_of_primes, 1900);
+}
+
+#[cfg(any(target_pointer_width = "32", target_pointer_width = "64"))]
+#[test]
+fn sieve_of_atkin_small_test() {
+    let num_of_primes = utils::SieveOfAtkin::new(10usize.pow(9)).iter().count();
+    assert_eq!(num_of_primes, 50847534);
+}
+
+#[cfg(target_pointer_width = "64")]
+#[test]
+fn sieve_of_atkin_large_test() {
+    let num_of_primes = utils::SieveOfAtkin::new(2usize.pow(36)).iter().count();
+    assert_eq!(num_of_primes, 2874398515);
+}
+
+#[test]
+fn continued_fraction_test() {
+    let fhandle = std::fs::File::open("res/continued_fraction_test.txt").unwrap();
+    let reader = std::io::BufReader::new(fhandle);
+    for line in reader.lines() {
+        let line = line.unwrap();
+        let mut num_terms = line.split_ascii_whitespace();
+        let num = num_terms.next().unwrap().parse().unwrap();
+        let terms = num_terms.next().unwrap().split(',').map(|s| s.parse().unwrap());
+        assert!(utils::ContinuedFraction::new(num).eq(terms));
+    }
+}
diff --git a/src/utils.rs b/src/utils.rs
index 377e335..1032c9f 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -1289,105 +1289,3 @@ impl Iterator for ContinuedFraction {
         Some(a)
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use crate::utils;
-    use std::io::BufRead;
-
-    #[cfg(target_pointer_width = "64")]
-    #[test]
-    fn is_prime_smaller_test() {
-        let num_of_primes = (0..2i64.pow(32)).filter(|&num| utils::is_prime(num)).count();
-        assert_eq!(num_of_primes, 203280221);
-    }
-
-    #[cfg(target_pointer_width = "64")]
-    #[test]
-    fn is_prime_small_test() {
-        let num_of_primes = (2i64.pow(32)..2i64.pow(33)).filter(|&num| utils::is_prime(num)).count();
-        assert_eq!(num_of_primes, 190335585);
-    }
-
-    #[test]
-    fn is_prime_large_test() {
-        let fhandle = std::fs::File::open("res/is_prime_large_test.txt").unwrap();
-        let reader = std::io::BufReader::new(fhandle);
-        for line in reader.lines() {
-            let line = line.unwrap();
-            let mut num_primality = line.split_ascii_whitespace();
-            let num = num_primality.next().unwrap().parse().unwrap();
-            let primality = num_primality.next().unwrap().parse().unwrap();
-            assert_eq!(utils::is_prime(num), primality);
-        }
-    }
-
-    #[test]
-    fn gcd_test() {
-        let fhandle = std::fs::File::open("res/gcd_test.txt").unwrap();
-        let reader = std::io::BufReader::new(fhandle);
-        for line in reader.lines() {
-            let line = line.unwrap();
-            let [a, b, g]: [i64; 3] = line
-                .split_ascii_whitespace()
-                .map(|s| s.parse().unwrap())
-                .collect::<Vec<i64>>()
-                .try_into()
-                .unwrap();
-            assert_eq!(a, utils::gcd(a, a));
-            assert_eq!(b, utils::gcd(b, b));
-            assert_eq!(g, utils::gcd(g, g));
-            assert_eq!(g, utils::gcd(a, b));
-            assert_eq!(g, utils::gcd(b, a));
-        }
-    }
-
-    #[test]
-    fn isqrt_test() {
-        assert_eq!(utils::isqrt(2i64.pow(53) - 1), 94906265);
-        assert_eq!(utils::isqrt(2i64.pow(54) - 1), 134217727);
-    }
-
-    #[test]
-    fn long_test() {
-        let mut num = &utils::Long::new("43").pow(37) * &utils::Long::from(745683);
-        num += &utils::Long::factorial(51);
-        assert_eq!(
-            num.to_string(),
-            "3597031455246992664728898500113748859466269359952342048214143659169"
-        );
-    }
-
-    #[test]
-    fn sieve_of_atkin_smaller_test() {
-        let num_of_primes = utils::SieveOfAtkin::new(2usize.pow(14)).iter().count();
-        assert_eq!(num_of_primes, 1900);
-    }
-
-    #[cfg(any(target_pointer_width = "32", target_pointer_width = "64"))]
-    #[test]
-    fn sieve_of_atkin_small_test() {
-        let num_of_primes = utils::SieveOfAtkin::new(10usize.pow(9)).iter().count();
-        assert_eq!(num_of_primes, 50847534);
-    }
-
-    #[cfg(target_pointer_width = "64")]
-    #[test]
-    fn sieve_of_atkin_large_test() {
-        let num_of_primes = utils::SieveOfAtkin::new(2usize.pow(36)).iter().count();
-        assert_eq!(num_of_primes, 2874398515);
-    }
-
-    #[test]
-    fn continued_fraction_test() {
-        let fhandle = std::fs::File::open("res/continued_fraction_test.txt").unwrap();
-        let reader = std::io::BufReader::new(fhandle);
-        for line in reader.lines() {
-            let line = line.unwrap();
-            let mut num_terms = line.split_ascii_whitespace();
-            let num = num_terms.next().unwrap().parse().unwrap();
-            let terms = num_terms.next().unwrap().split(',').map(|s| s.parse().unwrap());
-            assert!(utils::ContinuedFraction::new(num).eq(terms));
-        }
-    }
-}