diff --git a/cmake/SetBuildOptions.cmake b/cmake/SetBuildOptions.cmake
index c6b932369c..e70ec0456b 100644
--- a/cmake/SetBuildOptions.cmake
+++ b/cmake/SetBuildOptions.cmake
@@ -12,12 +12,12 @@ endif()
 
 # Check if MPI is present. This should succeed if
 # the compilers were set to mpifort and mpicc.
-find_package(MPI REQUIRED)
 
 # Set default compiler = GNU if none was specified. 
 if(NOT COMPILER)
     set(COMPILER "${CMAKE_Fortran_COMPILER_ID}" CACHE STRING "Choose compiler toolchain." FORCE)
     set_property(CACHE COMPILER PROPERTY STRINGS "GNU" "Intel")
+    set_property(CACHE COMPILER PROPERTY STRINGS "GNU" "Intel" "LFortran")
 endif()
 
 # Set compiler specific flags.
@@ -44,6 +44,11 @@ elseif(COMPILER STREQUAL "Intel" OR COMPILER STREQUAL "IntelLLVM")
       set(CMAKE_Fortran_FLAGS_DEBUG "-O0 -g -fpe0 -check all")
     endif()
     set(CMAKE_Fortran_FLAGS_RELEASE "-O2 -debug minimal")
+elseif(COMPILER STREQUAL "LFortran")
+    add_compile_definitions(CPRLFORTRAN)
+    # There is an issue, some modules require --cpp as a flag in their compilation
+    # some flat out break, if we put --cpp
+    # set(CMAKE_Fortran_FLAGS "--cpp")
 else()
     message(FATAL_ERROR "COMPILER='${COMPILER}' is not supported.")
 endif()
diff --git a/src/externals/gptl/CMakeLists.txt b/src/externals/gptl/CMakeLists.txt
index f882ded14d..f9dbd7c3b1 100644
--- a/src/externals/gptl/CMakeLists.txt
+++ b/src/externals/gptl/CMakeLists.txt
@@ -9,7 +9,7 @@ SET(TIMING_INCLUDE_DIRS   ${CMAKE_CURRENT_SOURCE_DIR}
     CACHE STRING "")
 INCLUDE_DIRECTORIES(${TIMING_INCLUDE_DIRS})
 
-ADD_DEFINITIONS(-DINCLUDE_CMAKE_FCI -DHAVE_MPI)
+ADD_DEFINITIONS(-DINCLUDE_CMAKE_FCI)
 
 SET(SRCS_C  GPTLget_memusage.c
             GPTLprint_memusage.c
diff --git a/src/externals/gptl/Makefile b/src/externals/gptl/Makefile
index 69372aea4e..8ea75c0f29 100644
--- a/src/externals/gptl/Makefile
+++ b/src/externals/gptl/Makefile
@@ -32,7 +32,6 @@ ifeq ($(strip $(MPILIB)), mpi-serial)
 else
   CC := $(MPICC)
   FC := $(MPIFC)
-  CPPDEFS += -DHAVE_MPI
 endif
 ifdef CPRE
   FPPDEFS := $(patsubst -D%,$(CPRE)%,$(CPPDEFS))
diff --git a/src/externals/gptl/perf_utils.F90 b/src/externals/gptl/perf_utils.F90
index 3aa29e80fb..d0430ded1c 100644
--- a/src/externals/gptl/perf_utils.F90
+++ b/src/externals/gptl/perf_utils.F90
@@ -164,9 +164,6 @@ SUBROUTINE shr_sys_flush(unit)
    call flush(unit)
 #endif
 #endif
-#if (defined AIX)
-   call flush_(unit)
-#endif
 
 END SUBROUTINE shr_sys_flush