diff --git a/arch/configure.defaults b/arch/configure.defaults
index e7a98362..f3c97669 100644
--- a/arch/configure.defaults
+++ b/arch/configure.defaults
@@ -2126,14 +2126,14 @@ NETCDFPAR_BUILD =       CONFIGURE_NETCDFPAR_BUILD
 ###########################################################
 #ARCH    Linux aarch64, GCC compiler OpenMPI # serial smpar dmpar dm+sm
 #
-DESCRIPTION     =      GCC ($SFC/$SCC): Aarch64
+DESCRIPTION     =      armclang ($SFC/$SCC): Aarch64
 DMPARALLEL      =
 OMPCPP          =      -fopenmp
 OMP             =      -fopenmp
 OMPCC           =      -fopenmp
-SFC             =      gfortran
-SCC             =      gcc
-CCOMP           =      gcc
+SFC             =      armflang
+SCC             =      armclang
+CCOMP           =      armclang
 DM_FC           =      mpif90
 DM_CC           =      mpicc -DMPI2_SUPPORT
 FC              =      CONFIGURE_FC
@@ -2141,17 +2141,15 @@ CC              =      CONFIGURE_CC
 LD              =      $(FC)
 RWORDSIZE       =      CONFIGURE_RWORDSIZE
 PROMOTION       =
-ARCH_LOCAL      =      -DAARCH64_X86_CORRECTNESS_FIX
+ARCH_LOCAL      =
 CFLAGS_LOCAL    =      -w -O3 -c
 LDFLAGS_LOCAL   =      -fopenmp
-FCOPTIM         =      -Ofast -mcpu=native -funroll-loops -fno-expensive-optimizations -fno-reciprocal-math -fsigned-zeros -fno-unsafe-math-optimizations
-# for graviton 2 use the folowing flag
-#FCOPTIM         =      -Ofast -march=armv8.2-a+fp16+rcpc+dotprod -funroll-loops -fno-expensive-optimizations -fno-reciprocal-math -fsigned-zeros -fno-unsafe-math-optimizations
+FCOPTIM         =      -Ofast -mcpu=native -funroll-loops
 FCREDUCEDOPT    =      $(FCOPTIM)
 FCNOOPT         =      -O0 -fopenmp -frecursive
 FCDEBUG         =      -g $(FCNOOPT)
-FORMAT_FIXED    =      -ffixed-form -ffixed-line-length-0 -fallow-argument-mismatch -fallow-invalid-boz
-FORMAT_FREE     =      -ffree-form -ffree-line-length-0 -fallow-argument-mismatch -fallow-invalid-boz
+FORMAT_FIXED    =      -ffixed-form -ffixed-line-length-0  
+FORMAT_FREE     =      -ffree-form -ffree-line-length-0 
 FCSUFFIX        =
 BYTESWAPIO      =      -fconvert=big-endian -frecord-marker=4
 FCBASEOPTS      =      -w $(FORMAT_FREE) $(BYTESWAPIO)
@@ -2165,6 +2163,7 @@ RANLIB          =      ranlib
 RLFLAGS         =
 CC_TOOLS        =      $(SCC)
 
+
 ###########################################################
 #ARCH    Linux aarch64, NVHPC compiler with nvc # serial smpar dmpar dm+sm
 #