diff --git a/DIRECTORY.md b/DIRECTORY.md
index e9c51452..430940f5 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -151,6 +151,7 @@
   * [PrimeCheck](https://github.com/TheAlgorithms/Java/blob/master/Maths/PrimeCheck.java)
   * [PrimeFactorization](https://github.com/TheAlgorithms/Java/blob/master/Maths/PrimeFactorization.java)
   * [PythagoreanTriple](https://github.com/TheAlgorithms/Java/blob/master/Maths/PythagoreanTriple.java)
+  * [SumOfArithmeticSeries](https://github.com/TheAlgorithms/Java/blob/master/Maths/SumOfArithmeticSeries.java)
   * [SumOfDigits](https://github.com/TheAlgorithms/Java/blob/master/Maths/SumOfDigits.java)
   * [VampireNumber](https://github.com/TheAlgorithms/Java/blob/master/Maths/VampireNumber.java)