diff --git a/math/deal.ii/Makefile b/math/deal.ii/Makefile
index a76b0fec4879..194ec73aae12 100644
--- a/math/deal.ii/Makefile
+++ b/math/deal.ii/Makefile
@@ -1,111 +1,116 @@
 PORTNAME=	deal.II
 DISTVERSION=	9.6.1
 CATEGORIES=	math
 MASTER_SITES=	https://github.com/dealii/dealii/releases/download/v${DISTVERSION}/
 DISTNAME=	dealii-${DISTVERSION}
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Finite element Differential Equations Analysis Library (DEAL)
 WWW=		https://www.dealii.org/ \
 		https://github.com/dealii/dealii
 
 LICENSE=	APACHE20 LGPL21
 LICENSE_COMB=	dual
 LICENSE_FILE_APACHE20=	${WRKSRC}/LICENSE.md
 LICENSE_FILE_LGPL21=	${WRKSRC}/LICENSE.md
 
 BROKEN_aarch64=		error: use of undeclared identifier '__TBB_machine_fetchadd4'
 BROKEN_armv7=		clang runs out of memory
 
 BUILD_DEPENDS=	${LOCALBASE}/include/boost/config.hpp:devel/boost-libs
 LIB_DEPENDS=	libblis.so:math/blis \
 		libboost_serialization.so:devel/boost-libs \
 		libhdf5.so:science/hdf5 \
 		libmetis.so:math/metis \
 		libvtkCommonCore-${VTK_VER}.so:math/vtk${VTK_VER:R}
 #		libkokkoscore.so:devel/kokkos TMP commented out for bundled kokkos, tests fail for non-bundled kokkos, see https://github.com/dealii/dealii/issues/15692
 
 USES=		blaslapack cmake:testing compiler:c++17-lang localbase:ldflags xorg
 USE_LDCONFIG=	yes
 
 CMAKE_OFF=	DEAL_II_ALLOW_BUNDLED DEAL_II_COMPONENT_EXAMPLES \
 		DEAL_II_WITH_P4EST DEAL_II_WITH_TRILINOS DEAL_II_WITH_UMFPACK \
 		DEAL_II_WITH_NANOFLANN DEAL_II_WITH_MUPARSER DEAL_II_WITH_ASSIMP \
 		DEAL_II_WITH_HDF5
 CMAKE_ON=	DEAL_II_FORCE_BUNDLED_TBB # instead of LIB_DEPENDS+=libtbb.so:devel/onetbb, pending https://github.com/dealii/dealii/issues/11561
 CMAKE_ON+=	FORCE_BUNDLED_KOKKOS # TMP turn on bundled kokkos
 CMAKE_TESTING_ON=	FREEBSD_ENABLE_TESTS
 
 LDFLAGS+=	-lomp
 LDFLAGS+=	-lexecinfo # TMP for bundled kokkos
 
+XARCH!=		uname -p
+
 OPTIONS_DEFINE=		ADOLC ARPACK GSL LAPACK MPI OPENCASCADE PETSC SCALAPACK SLEPC SUNDIALS # for all options see contrib/docker/Dockerfile, TODO some of them need to be enabled here
 OPTIONS_DEFAULT=	GSL LAPACK MPI OPENCASCADE PETSC SCALAPACK SLEPC SUNDIALS
 
 ADOLC_DESC=		Compile with ADOL-C
 ADOLC_CMAKE_BOOL=	DEAL_II_WITH_ADOLC
 ADOLC_LIB_DEPENDS=	libadolc.so:math/adol-c
 ADOLC_BROKEN=		requires the development version: see https://github.com/dealii/dealii/issues/7293
 
 ARPACK_DESC=		Compile with Arpack and PArpack (only with MPI, LAPACK)
 ARPACK_CMAKE_BOOL=	DEAL_II_WITH_ARPACK
 ARPACK_CMAKE_ON=	-DARPACK_LINKER_FLAGS:STRING="${LDFLAGS}"
 ARPACK_BUILD_DEPENDS=	arpack-ng>0:math/arpack-ng
 ARPACK_RUN_DEPENDS=	arpack-ng>0:math/arpack-ng # itself doesn't link to arpack, but makes depending project link to it
 ARPACK_IMPLIES=		LAPACK
 
 GSL_DESC=		Compile with gsl
 GSL_CMAKE_BOOL=		DEAL_II_WITH_GSL
 GSL_LIB_DEPENDS=	libgsl.so:math/gsl
 
 LAPACK_DESC=		Compile with LAPACK for matrix operations
 LAPACK_USES=		fortran
 LAPACK_CMAKE_BOOL=	DEAL_II_WITH_LAPACK
 LAPACK_CMAKE_ON=	-DLAPACK_LINKER_FLAGS:STRING="${LDFLAGS}"
 LAPACK_LIB_DEPENDS=	libopenblas.so:math/openblas
 
 MPI_DESC=		MPI support (math/sundials must be compiled with MPI)
 MPI_USES=		fortran
 MPI_CMAKE_BOOL=		DEAL_II_WITH_MPI
 MPI_CMAKE_ON=		-DMPI_LINKER_FLAGS:STRING="${LDFLAGS}"
 MPI_LIB_DEPENDS=	libboost_iostreams.so:devel/boost-libs \
 			libmpich.so:net/mpich
 
 OPENCASCADE_DESC=	Compile with OpenCascade
 OPENCASCADE_CMAKE_BOOL=	DEAL_II_WITH_OPENCASCADE
 OPENCASCADE_CMAKE_ON=	-DOPENCASCADE_INCLUDE_DIR:STRING=${LOCALBASE}/include/OpenCASCADE
 OPENCASCADE_LIB_DEPENDS=	libTKernel.so:cad/opencascade
 
 PETSC_DESC=		Compile with Petsc (only with MPI)
 PETSC_USES=		xorg
 PETSC_USE=		XORG=x11 # PETSc adds x11 through interface libraries
-PETSC_CMAKE_BOOL=	DEAL_II_WITH_PETSC DEAL_II_WITH_64BIT_INDICES
+PETSC_CMAKE_BOOL=	DEAL_II_WITH_PETSC
 PETSC_LIB_DEPENDS=	libpetsc.so:science/PETSc
 PETSC_IMPLIES=		MPI # has to use the same MPI as PETSc uses
+.if ${XARCH:M*64*} # match index size width being set to 64 in science/PETSc and math/metis
+PETSC_CMAKE_BOOL+=	DEAL_II_WITH_64BIT_INDICES # as opposed to 32-bit indices that are default in deal.II
+.endif
 
 SCALAPACK_DESC=		Compile with ScaLAPACK (only with MPI)
 SCALAPACK_CMAKE_BOOL=	DEAL_II_WITH_SCALAPACK
 SCALAPACK_IMPLIES=	MPI LAPACK
 SCALAPACK_LIB_DEPENDS=	libscalapack.so:math/scalapack
 
 SLEPC_DESC=		Compile with Slepc (only with MPI)
 SLEPC_USES=		xorg
 SLEPC_USE=		XORG=x11 # SLEPc adds x11 through interface libraries
 SLEPC_CMAKE_BOOL=	DEAL_II_WITH_SLEPC
 SLEPC_LIB_DEPENDS=	libslepc.so:math/slepc
 SLEPC_IMPLIES=		MPI # has to use the same MPI as PETSc uses
 
 SUNDIALS_DESC=		Compile with SUNDIALS
 SUNDIALS_CMAKE_BOOL=	DEAL_II_WITH_SUNDIALS
 SUNDIALS_LIB_DEPENDS=	libsundials_arkode.so:math/sundials
 
 post-patch: # unbundle boost
 	@${RM} -r ${WRKSRC}/dealii/bundled/boost-*
 
 post-stage:
 	@${RM} ${STAGEDIR}${PREFIX}/*.log
 
 # the testsuite is excluded from the tarball: https://github.com/dealii/dealii/issues/17951
 
 .include <../../math/vtk9/Makefile.version>
 .include <bsd.port.mk>