diff --git a/CHANGELOG.md b/CHANGELOG.md
index e721631..03afd32 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+### Changed
+
+### Deprecated
+
+## [4.0.0] - 2024-05-21
+
+### Added
+
 - Add FMS as a library rather than part of Baselibs
 - Added `Findlibyaml.cmake` to support FMS with yaml support
   - FMS with YAML support is controlled by `-DFMS_BUILT_WITH_YAML` as there is no good way to determine how FMS was built
@@ -21,10 +29,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Change the minimum required GCC compiler version to be 11.2
+- Change the minumum required NAG compiler verison to be 7.2
 - Update CI to use Baselibs v8.0.2
 
-### Deprecated
-
 ## [3.45.2] - 2024-05-16
 
 ### Fixed
diff --git a/compiler/flags/GNU_Fortran.cmake b/compiler/flags/GNU_Fortran.cmake
index 3d292ae..36fd0a1 100644
--- a/compiler/flags/GNU_Fortran.cmake
+++ b/compiler/flags/GNU_Fortran.cmake
@@ -1,5 +1,5 @@
-if (CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 8.3)
-  message(FATAL_ERROR "${CMAKE_Fortran_COMPILER_ID} version must be at least 8.3!")
+if (CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 10.3)
+  message(FATAL_ERROR "${CMAKE_Fortran_COMPILER_ID} version must be at least 10.3!")
 endif()
 
 set (FOPT0 "-O0")
diff --git a/compiler/flags/NAG_Fortran.cmake b/compiler/flags/NAG_Fortran.cmake
index 0296c9b..70a9831 100644
--- a/compiler/flags/NAG_Fortran.cmake
+++ b/compiler/flags/NAG_Fortran.cmake
@@ -1,5 +1,5 @@
-if (CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 6.0)
-  message(FATAL_ERROR "${CMAKE_Fortran_COMPILER_ID} version must be at least 6.0!")
+if (CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 7.2)
+  message(FATAL_ERROR "${CMAKE_Fortran_COMPILER_ID} version must be at least 7.2!")
 endif()
 
 set (FREAL8 "-r8")