diff --git a/CMakeLists.txt b/CMakeLists.txt
index ecf2fd4..6769952 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.13 FATAL_ERROR)
 
-project(BabelStream VERSION 3.5 LANGUAGES CXX)
+project(BabelStream VERSION 4.0 LANGUAGES CXX)
 
 # uncomment for debugging build issues:
 #set(CMAKE_VERBOSE_MAKEFILE ON)
diff --git a/src/main.cpp b/src/main.cpp
index 13a0021..3035da0 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -15,7 +15,7 @@
 #include <iomanip>
 #include <cstring>
 
-#define VERSION_STRING "3.4"
+#define VERSION_STRING "4.0"
 
 #include "Stream.h"