diff --git a/tests/test_prime_fact.py b/tests/test_prime_fact.py
index 285f9c0..1e1c3f7 100644
--- a/tests/test_prime_fact.py
+++ b/tests/test_prime_fact.py
@@ -12,10 +12,24 @@
 class TestPrimeFact(unittest.TestCase):
     """Test cases for prime_fact module"""
 
+    def primefact_selfcheck(self, N):
+        from collections import Counter
+
+        PF = prime_fact.prime_fact(N)
+        M = 1
+        for p, e in PF.items():
+            M *= pow(p, e)
+        self.assertEqual(N, M)
+
     def test_prime_factorization(self):
-        """Test prime factorization functionality"""
-        # TODO: Add test cases for prime factorization
-        pass
+        for n in range(1, 10**5):
+            self.primefact_selfcheck(n)
+
+        for n in range(10**9, 10**9 + 1000):
+            self.primefact_selfcheck(n)
+
+        for n in range(10**17, 10**17 + 1000):
+            self.primefact_selfcheck(n)
 
     def is_prime_example(self):
         numList = [1, 2, 3, 4, 998244353, 1000000000000000000]