diff --git a/data_structures/dsu_union_rank.cpp b/data_structures/dsu_union_rank.cpp
index 8936d6d69..4ca53bb76 100644
--- a/data_structures/dsu_union_rank.cpp
+++ b/data_structures/dsu_union_rank.cpp
@@ -20,6 +20,7 @@
  */
 
 #include <cassert>   /// for assert
+#include <cstdint>   /// for integral typedefs
 #include <iostream>  /// for IO operations
 #include <vector>    /// for std::vector