diff --git a/DESCRIPTION b/DESCRIPTION
index a204550..43374d4 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -27,7 +27,7 @@ Imports: Rcpp (>= 0.11.2), Matrix, methods, survival
 LinkingTo: Rcpp, RcppEigen
 Depends: R (>= 3.1)
 Suggests: testthat
-RoxygenNote: 7.2.2
+RoxygenNote: 7.3.2
 Encoding: UTF-8
 NeedsCompilation: yes
 URL: https://github.com/bips-hb/blockForest, https://bips-hb.github.io/blockForest/
diff --git a/src/Makevars b/src/Makevars
index a77f239..016e9d5 100644
--- a/src/Makevars
+++ b/src/Makevars
@@ -1,2 +1,3 @@
 PKG_CPPFLAGS = -DR_BUILD
-
+CXX_STD = CXX20
+PKG_CXXFLAGS = -std=c++20
diff --git a/src/utility.h b/src/utility.h
index e054850..deb6d6c 100644
--- a/src/utility.h
+++ b/src/utility.h
@@ -20,6 +20,10 @@
 #ifndef UTILITY_H_
 #define UTILITY_H_
 
+#ifdef R_BUILD
+#include <Rcpp.h>
+#endif 
+
 #include <vector>
 #include <iostream>
 #include <fstream>
@@ -28,10 +32,6 @@
 #include <unordered_set>
 #include <unordered_map>
 
-#ifdef R_BUILD
-#include <Rinternals.h>
-#endif
-
 #include "globals.h"
 #include "Data.h"