diff --git a/DIRECTORY.md b/DIRECTORY.md
index c796ea9cb..906ab4636 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -203,6 +203,7 @@
 ## ProjectEuler
   * [Problem01](https://github.com/TheAlgorithms/Java/blob/master/ProjectEuler/Problem01.java)
   * [Problem02](https://github.com/TheAlgorithms/Java/blob/master/ProjectEuler/Problem02.java)
+  * [Problem04](https://github.com/TheAlgorithms/Java/blob/master/ProjectEuler/Problem04.java)
 
 ## Searches
   * [BinarySearch](https://github.com/TheAlgorithms/Java/blob/master/Searches/BinarySearch.java)