diff --git a/AMSS_NCKU_source/TwoPunctures.C b/AMSS_NCKU_source/TwoPunctures.C
index 1b6e590..9101183 100644
--- a/AMSS_NCKU_source/TwoPunctures.C
+++ b/AMSS_NCKU_source/TwoPunctures.C
@@ -27,7 +27,7 @@ using namespace std;
 #endif
 
 #include "TwoPunctures.h"
-#include <mkl_cblas.h>
+#include <cblas.h>
 
 TwoPunctures::TwoPunctures(double mp, double mm, double b,
                            double P_plusx, double P_plusy, double P_plusz,
diff --git a/AMSS_NCKU_source/gaussj.C b/AMSS_NCKU_source/gaussj.C
index 86c7777..885284f 100644
--- a/AMSS_NCKU_source/gaussj.C
+++ b/AMSS_NCKU_source/gaussj.C
@@ -17,8 +17,8 @@ using namespace std;
 #include <math.h>
 #endif
 
-// Intel oneMKL LAPACK interface
-#include <mkl_lapacke.h>
+// LAPACKE interface (AOCL for AOCC, oneMKL for Intel)
+#include <lapacke.h>
 /* Linear equation solution using Intel oneMKL LAPACK.
 a[0..n-1][0..n-1] is the input matrix. b[0..n-1] is input
 containing the right-hand side vectors. On output a is
diff --git a/AMSS_NCKU_source/makefile b/AMSS_NCKU_source/makefile
index b3f6914..6842b0f 100644
--- a/AMSS_NCKU_source/makefile
+++ b/AMSS_NCKU_source/makefile
@@ -36,6 +36,16 @@ endif
 
 TP_OPTFLAGS = -O3 -xHost -fp-model fast=2 -fma -ipo \
               -Dfortran3 -Dnewc $(MKL_INC)
+else ifeq ($(TOOLCHAIN),aocc)
+## AMD AOCC build flags optimized for EPYC Zen 5 (-march=znver5)
+## PGO_MODE is ignored in this branch.
+OMP_FLAG = -fopenmp
+CXXAPPFLAGS = -O3 -march=znver5 -ffast-math -flto \
+              -Dfortran3 -Dnewc -I$(AOCL_ROOT)/include $(INTERP_LB_FLAGS)
+f90appflags = -O3 -march=znver5 -ffast-math -flto \
+              -cpp -I$(AOCL_ROOT)/include $(POLINT6_FLAG)
+TP_OPTFLAGS = -O3 -march=znver5 -ffast-math -flto \
+              -Dfortran3 -Dnewc -I$(AOCL_ROOT)/include
 else
 ## NVHPC defaults: mpicc/mpicxx/mpifort wrappers
 ## PGO_MODE is ignored in this branch.
diff --git a/AMSS_NCKU_source/makefile.inc b/AMSS_NCKU_source/makefile.inc
index 54bc86c..5ea42a7 100755
--- a/AMSS_NCKU_source/makefile.inc
+++ b/AMSS_NCKU_source/makefile.inc
@@ -1,6 +1,7 @@
 ## Toolchain selection
-##   nvhpc : NVIDIA HPC SDK + CUDA-aware MPI (default)
+##   nvhpc : NVIDIA HPC SDK + CUDA-aware MPI
 ##   intel : Intel oneAPI toolchain (legacy path)
+##   aocc  : AMD AOCC + AOCL + OpenMPI (for AMD EPYC Zen 5, with CUDA)
 TOOLCHAIN ?= intel
 
 ## PGO build mode switch (ABE only; TwoPunctureABE always uses opt flags)
@@ -26,6 +27,10 @@ MKLROOT ?= /home/intel/oneapi/mkl/latest
 MKL_LIBDIR ?= $(MKLROOT)/lib/intel64
 MKL_INC ?= -I$(MKLROOT)/include
 
+## AMD AOCC toolchain paths (used when TOOLCHAIN=aocc)
+AOCL_ROOT ?= /home/aocc/aocl/5.2.0/aocc
+OMPI_PREFIX ?= /home/aocc/aocc-openmpi
+
 NVHPC_ROOT ?= /home/nvidia/hpc_sdk/Linux_x86_64/25.11
 CUDA_HOME  ?= $(NVHPC_ROOT)/cuda
 CUDA_ARCH  ?= sm_80
@@ -67,6 +72,16 @@ LDLIBS       = -L$(MKL_LIBDIR) -Wl,-rpath,$(MKL_LIBDIR) \
                -lmkl_intel_lp64 -lmkl_sequential -lmkl_core \
                -lifcore -limf -liomp5 -lpthread -lm -ldl \
                -L$(CUDA_HOME)/lib64 -Wl,-rpath,$(CUDA_HOME)/lib64 -lcuda -lcudart
+else ifeq ($(TOOLCHAIN),aocc)
+f90          = flang
+f77          = flang
+CXX          = clang++
+CC           = clang
+CLINKER      = $(OMPI_PREFIX)/bin/mpicxx
+filein       = -I/usr/include/ -I$(AOCL_ROOT)/include -I$(CUDA_HOME)/include
+LDLIBS       = -L$(AOCL_ROOT)/lib -lblis -lflame -lamdlibm -lflang -lpgmath \
+               -ljemalloc -lpthread -lm -ldl -lomp \
+               -L$(CUDA_HOME)/lib64 -Wl,-rpath,$(CUDA_HOME)/lib64 -lcuda -lcudart
 else ifeq ($(TOOLCHAIN),nvhpc)
 f90          = mpifort
 f77          = mpifort
@@ -82,9 +97,11 @@ LDLIBS       = -L$(MKL_LIBDIR) -Wl,-rpath,$(MKL_LIBDIR) \
                -fortranlibs
 endif
 
+ifeq ($(TOOLCHAIN),intel)
 ifeq ($(USE_TBBMALLOC),1)
 LDLIBS := $(TBBMALLOC_LIBS) $(LDLIBS)
 endif
+endif
 
 Cu = $(NVHPC_ROOT)/compilers/bin/nvcc
 CUDA_LIB_PATH = -L$(CUDA_HOME)/lib64 -I$(CUDA_HOME)/include