diff --git a/CMakeLists.txt b/CMakeLists.txt
index b59ec7a7..5e0d9c0f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,7 +4,7 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/")
 include(guidelineSupportLibrary)
 
 project(GSL
-    VERSION 3.1.0
+    VERSION 4.0.0
     LANGUAGES CXX
 )