diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 76c03556..91be7742 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -58,13 +58,9 @@ if(${CMAKE_Fortran_COMPILER_ID} STREQUAL "PGI" OR
   target_compile_options(xcompact PRIVATE "-DCUDA")
 elseif(${CMAKE_Fortran_COMPILER_ID} STREQUAL "GNU")
   if (NOT FLAGS_SET)
-	  # set(OpenMP_Fortran_FLAGS "-fopenmp" CACHE STRING "" FORCE)
-    	  # set(OpenMP_Fortran_LIB_NAMES "gomp" CACHE STRING "" FORCE)
-    	  # set(OpenMP_gomp_LIBRARY "-lgomp" CACHE STRING "" FORCE)
-
-    set(CMAKE_Fortran_FLAGS "-cpp -fallow-argument-mismatch" CACHE STRING "" FORCE)
-    set(CMAKE_Fortran_FLAGS_DEBUG "-g -Og -Wall -Wpedantic -Werror -Wimplicit-interface -Wimplicit-procedure -Wno-unused-dummy-argument" CACHE STRING "" FORCE)
-    set(CMAKE_Fortran_FLAGS_RELEASE "-O3 -ffast-math -march=native" CACHE STRING "" FORCE)
+    set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -cpp -std=f2018 -fallow-argument-mismatch" CACHE STRING "" FORCE)
+    set(CMAKE_Fortran_FLAGS_DEBUG "${CMAKE_Fortran_FLAGS_DEBUG} -g -Og -Wall -Wpedantic -Werror -Wimplicit-interface -Wimplicit-procedure -Wno-unused-dummy-argument" CACHE STRING "" FORCE)
+    set(CMAKE_Fortran_FLAGS_RELEASE "${CMAKE_Fortran_FLAGS_RELEASE} -O3 -ffast-math -march=native" CACHE STRING "" FORCE)
     set(FLAGS_SET 1 CACHE INTERNAL "")
   endif()
 endif()