diff --git a/cmake/Modules/SetFortranFlags.cmake b/cmake/Modules/SetFortranFlags.cmake
index 836747fd3..891a878f4 100644
--- a/cmake/Modules/SetFortranFlags.cmake
+++ b/cmake/Modules/SetFortranFlags.cmake
@@ -218,9 +218,9 @@ SET_COMPILE_FLAG(CMAKE_Fortran_FLAGS_DEBUG "${CMAKE_Fortran_FLAGS_DEBUG}"
 #####################
 
 # Optimizations
-SET_COMPILE_FLAG(CMAKE_Fortran_FLAGS_TESTING "${CMAKE_Fortran_FLAGS_TESTING}"
-                 Fortran REQUIRED "-O2" # All compilers not on Windows
-                                  "/O2" # Intel Windows
+SET_COMPILE_FLAG(CMAKE_Fortran_FLAGS_TESTING "${CMAKE_Fortran_FLAGS_DEBUG}"
+                 Fortran REQUIRED "-O3" # All compilers not on Windows
+                                  "/O3" # Intel Windows
                 )
 
 #####################