diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index cc9b3fc56a..b1d90af045 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -189,11 +189,11 @@ if(BUILD_MPI)
   else()
     find_package(MPI REQUIRED)
     include_directories(${MPI_CXX_INCLUDE_PATH})
-    add_definitions(-DMPICH_SKIP_MPICXX -DOMPI_SKIP_MPICXX=1)
+    target_compile_definitions(lammps PRIVATE -DMPICH_SKIP_MPICXX -DOMPI_SKIP_MPICXX=1)
     target_link_libraries(lammps PUBLIC MPI::MPI_CXX)
     option(LAMMPS_LONGLONG_TO_LONG "Workaround if your system or MPI version does not recognize 'long long' data types" OFF)
     if(LAMMPS_LONGLONG_TO_LONG)
-      add_definitions(-DLAMMPS_LONGLONG_TO_LONG)
+      target_compile_definitions(lammps PRIVATE -DLAMMPS_LONGLONG_TO_LONG)
     endif()
   endif()
 else()
@@ -209,7 +209,7 @@ set(LAMMPS_SIZES_VALUES smallbig bigbig smallsmall)
 set_property(CACHE LAMMPS_SIZES PROPERTY STRINGS ${LAMMPS_SIZES_VALUES})
 validate_option(LAMMPS_SIZES LAMMPS_SIZES_VALUES)
 string(TOUPPER ${LAMMPS_SIZES} LAMMPS_SIZES)
-add_definitions(-DLAMMPS_${LAMMPS_SIZES})
+target_compile_definitions(lammps PRIVATE -DLAMMPS_${LAMMPS_SIZES})
 set(LAMMPS_API_DEFINES "${LAMMPS_API_DEFINES} -DLAMMPS_${LAMMPS_SIZES}")
 
 # posix_memalign is not available on Windows
@@ -219,12 +219,12 @@ else()
   set(LAMMPS_MEMALIGN "64" CACHE STRING "enables the use of the posix_memalign() call instead of malloc() when large chunks or memory are allocated by LAMMPS. Set to 0 to disable")
 endif()
 if(NOT ${LAMMPS_MEMALIGN} STREQUAL "0")
-  add_definitions(-DLAMMPS_MEMALIGN=${LAMMPS_MEMALIGN})
+  target_compile_definitions(lammps PRIVATE -DLAMMPS_MEMALIGN=${LAMMPS_MEMALIGN})
 endif()
 
 option(LAMMPS_EXCEPTIONS "enable the use of C++ exceptions for error messages (useful for library interface)" OFF)
 if(LAMMPS_EXCEPTIONS)
-  add_definitions(-DLAMMPS_EXCEPTIONS)
+  target_compile_definitions(lammps PUBLIC -DLAMMPS_EXCEPTIONS)
   set(LAMMPS_API_DEFINES "${LAMMPS_API_DEFINES} -DLAMMPS_EXCEPTIONS")
 endif()
 
@@ -283,7 +283,7 @@ find_package(JPEG QUIET)
 option(WITH_JPEG "Enable JPEG support" ${JPEG_FOUND})
 if(WITH_JPEG)
   find_package(JPEG REQUIRED)
-  add_definitions(-DLAMMPS_JPEG)
+  target_compile_definitions(lammps PRIVATE -DLAMMPS_JPEG)
   if(CMAKE_VERSION VERSION_LESS 3.12)
     include_directories(${JPEG_INCLUDE_DIR})
     target_link_libraries(lammps PRIVATE ${JPEG_LIBRARIES})
@@ -303,7 +303,7 @@ if(WITH_PNG)
   find_package(PNG REQUIRED)
   find_package(ZLIB REQUIRED)
   target_link_libraries(lammps PRIVATE PNG::PNG ZLIB::ZLIB)
-  add_definitions(-DLAMMPS_PNG)
+  target_compile_definitions(lammps PRIVATE -DLAMMPS_PNG)
 endif()
 
 find_program(GZIP_EXECUTABLE gzip)
@@ -313,7 +313,7 @@ if(WITH_GZIP)
   if(NOT GZIP_FOUND)
     message(FATAL_ERROR "gzip executable not found")
   endif()
-  add_definitions(-DLAMMPS_GZIP)
+  target_compile_definitions(lammps PRIVATE -DLAMMPS_GZIP)
 endif()
 
 find_program(FFMPEG_EXECUTABLE ffmpeg)
@@ -323,7 +323,7 @@ if(WITH_FFMPEG)
   if(NOT FFMPEG_FOUND)
     message(FATAL_ERROR "ffmpeg executable not found")
   endif()
-  add_definitions(-DLAMMPS_FFMPEG)
+  target_compile_definitions(lammps PRIVATE -DLAMMPS_FFMPEG)
 endif()
 
 if(BUILD_SHARED_LIBS)
@@ -413,7 +413,7 @@ endforeach()
 # packages that need defines set
 foreach(PKG MPIIO)
   if(PKG_${PKG})
-    add_definitions(-DLMP_${PKG})
+    target_compile_definitions(lammps PRIVATE -DLMP_${PKG})
   endif()
 endforeach()
 
diff --git a/cmake/Modules/MPI4WIN.cmake b/cmake/Modules/MPI4WIN.cmake
index 1fe6daada3..a02adca77d 100644
--- a/cmake/Modules/MPI4WIN.cmake
+++ b/cmake/Modules/MPI4WIN.cmake
@@ -16,7 +16,7 @@ else()
 endif()
 
 ExternalProject_get_property(mpi4win_build SOURCE_DIR)
-add_definitions(-DMPICH_SKIP_MPICXX)
+target_compile_definitions(lammps PRIVATE -DMPICH_SKIP_MPICXX)
 include_directories("${SOURCE_DIR}/include")
 set(MPI4WIN_LIBRARIES "${SOURCE_DIR}/lib/libmpi.a")
 add_dependencies(lammps mpi4win_build)
diff --git a/cmake/Modules/Packages/KIM.cmake b/cmake/Modules/Packages/KIM.cmake
index 56fc1449fa..7d349f496b 100644
--- a/cmake/Modules/Packages/KIM.cmake
+++ b/cmake/Modules/Packages/KIM.cmake
@@ -3,16 +3,16 @@ if(PKG_KIM)
   find_package(CURL)
   if(CURL_FOUND)
     target_link_libraries(lammps PRIVATE CURL::libcurl) 
-    add_definitions(-DLMP_KIM_CURL)
+    target_compile_definitions(lammps PRIVATE -DLMP_KIM_CURL)
     set(LMP_DEBUG_CURL OFF CACHE STRING "Set libcurl verbose mode on/off. If on, it displays a lot of verbose information about its operations.")
     mark_as_advanced(LMP_DEBUG_CURL)
     if(LMP_DEBUG_CURL)
-      add_definitions(-DLMP_DEBUG_CURL)
+      target_compile_definitions(lammps PRIVATE -DLMP_DEBUG_CURL)
     endif()
     set(LMP_NO_SSL_CHECK OFF CACHE STRING "Tell libcurl to not verify the peer. If on, the connection succeeds regardless of the names in the certificate. Insecure - Use with caution!")
     mark_as_advanced(LMP_NO_SSL_CHECK)
     if(LMP_NO_SSL_CHECK)
-      add_definitions(-DLMP_NO_SSL_CHECK)
+      target_compile_definitions(lammps PRIVATE -DLMP_NO_SSL_CHECK)
     endif()
   endif()
   find_package(KIM-API QUIET)
diff --git a/cmake/Modules/Packages/KOKKOS.cmake b/cmake/Modules/Packages/KOKKOS.cmake
index 58d2c139f6..34c924790e 100644
--- a/cmake/Modules/Packages/KOKKOS.cmake
+++ b/cmake/Modules/Packages/KOKKOS.cmake
@@ -18,7 +18,7 @@ if(PKG_KOKKOS)
     include_directories(${Kokkos_INCLUDE_DIRS})
     target_link_libraries(lammps PRIVATE kokkos)
   endif()
-  add_definitions(-DLMP_KOKKOS)
+  target_compile_definitions(lammps PRIVATE -DLMP_KOKKOS)
 
   set(KOKKOS_PKG_SOURCES_DIR ${LAMMPS_SOURCE_DIR}/KOKKOS)
   set(KOKKOS_PKG_SOURCES ${KOKKOS_PKG_SOURCES_DIR}/kokkos.cpp
@@ -44,7 +44,7 @@ if(PKG_KOKKOS)
                                    ${KOKKOS_PKG_SOURCES_DIR}/remap_kokkos.cpp)
     if(KOKKOS_ENABLE_CUDA)
       if(NOT ${FFT} STREQUAL "KISS")
-        add_definitions(-DFFT_CUFFT)
+        target_compile_definitions(lammps PRIVATE -DFFT_CUFFT)
 	target_link_libraries(lammps PRIVATE cufft)
       endif()
     endif()
diff --git a/cmake/Modules/Packages/KSPACE.cmake b/cmake/Modules/Packages/KSPACE.cmake
index 2a586dccf3..e2a42f3981 100644
--- a/cmake/Modules/Packages/KSPACE.cmake
+++ b/cmake/Modules/Packages/KSPACE.cmake
@@ -3,7 +3,7 @@ if(PKG_KSPACE)
   set(FFTW "FFTW3")
   if(FFT_SINGLE)
     set(FFTW "FFTW3F")
-    add_definitions(-DFFT_SINGLE)
+    target_compile_definitions(lammps PUBLIC -DFFT_SINGLE)
   endif()
   find_package(${FFTW} QUIET)
   if(${FFTW}_FOUND)
@@ -18,7 +18,7 @@ if(PKG_KSPACE)
 
   if(FFT STREQUAL "FFTW3")
     find_package(${FFTW} REQUIRED)
-    add_definitions(-DFFT_FFTW3)
+    target_compile_definitions(lammps PUBLIC -DFFT_FFTW3)
     target_link_libraries(lammps PUBLIC ${FFTW}::${FFTW})
     if(FFTW3_OMP_LIBRARY OR FFTW3F_OMP_LIBRARY)
       option(FFT_FFTW_THREADS "Use threaded FFTW library" ON)
@@ -28,7 +28,7 @@ if(PKG_KSPACE)
 
     if(FFT_FFTW_THREADS)
       if(FFTW3_OMP_LIBRARY OR FFTW3F_OMP_LIBRARY)
-        add_definitions(-DFFT_FFTW_THREADS)
+	target_compile_definitions(lammps PRIVATE -DFFT_FFTW_THREADS)
 	target_link_libraries(lammps PRIVATE ${FFTW}::${FFTW}_OMP)
       else()
         message(FATAL_ERROR "Need OpenMP enabled FFTW3 library for FFT_THREADS")
@@ -36,16 +36,16 @@ if(PKG_KSPACE)
     endif()
   elseif(FFT STREQUAL "MKL")
     find_package(MKL REQUIRED)
-    add_definitions(-DFFT_MKL)
+    target_compile_definitions(lammps PRIVATE -DFFT_MKL)
     option(FFT_MKL_THREADS "Use threaded MKL FFT" ON)
     if(FFT_MKL_THREADS)
-      add_definitions(-DFFT_MKL_THREADS)
+      target_compile_definitions(lammps PRIVATE -DFFT_MKL_THREADS)
     endif()
     include_directories(${MKL_INCLUDE_DIRS})
     target_link_libraries(lammps PRIVATE ${MKL_LIBRARIES})
   else()
     # last option is KISSFFT
-    add_definitions(-DFFT_KISS)
+    target_compile_definitions(lammps PRIVATE -DFFT_KISS)
   endif()
 
   set(FFT_PACK "array" CACHE STRING "Optimization for FFT")
@@ -54,6 +54,6 @@ if(PKG_KSPACE)
   validate_option(FFT_PACK FFT_PACK_VALUES)
   if(NOT FFT_PACK STREQUAL "array")
     string(TOUPPER ${FFT_PACK} FFT_PACK)
-    add_definitions(-DFFT_PACK_${FFT_PACK})
+    target_compile_definitions(lammps PRIVATE -DFFT_PACK_${FFT_PACK})
   endif()
 endif()
diff --git a/cmake/Modules/Packages/PYTHON.cmake b/cmake/Modules/Packages/PYTHON.cmake
index 7d6e2999f7..4611fddb98 100644
--- a/cmake/Modules/Packages/PYTHON.cmake
+++ b/cmake/Modules/Packages/PYTHON.cmake
@@ -1,6 +1,6 @@
 if(PKG_PYTHON)
   find_package(PythonLibs REQUIRED)
-  add_definitions(-DLMP_PYTHON)
+  target_compile_definitions(lammps PRIVATE -DLMP_PYTHON)
   include_directories(${PYTHON_INCLUDE_DIR})
   target_link_libraries(lammps PRIVATE ${PYTHON_LIBRARY})
 endif()
diff --git a/cmake/Modules/Packages/USER-INTEL.cmake b/cmake/Modules/Packages/USER-INTEL.cmake
index 0a9b634bc7..96a897297f 100644
--- a/cmake/Modules/Packages/USER-INTEL.cmake
+++ b/cmake/Modules/Packages/USER-INTEL.cmake
@@ -4,7 +4,7 @@ if(PKG_USER-INTEL)
     message(FATAL_ERROR "immintrin.h header not found, Intel package won't work without it")
   endif()
 
-  add_definitions(-DLMP_USER_INTEL)
+  target_compile_definitions(lammps PRIVATE -DLMP_USER_INTEL)
 
   set(INTEL_ARCH "cpu" CACHE STRING "Architectures used by USER-INTEL (cpu or knl)")
   set(INTEL_ARCH_VALUES cpu knl)
@@ -24,14 +24,14 @@ if(PKG_USER-INTEL)
   string(TOUPPER ${INTEL_LRT_MODE} INTEL_LRT_MODE)
   if(INTEL_LRT_MODE STREQUAL "THREADS")
     if(Threads_FOUND)
-      add_definitions(-DLMP_INTEL_USELRT)
+      target_compile_definitions(lammps PRIVATE -DLMP_INTEL_USELRT)
       target_link_libraries(lammps PRIVATE Threads::Threads)
     else()
       message(FATAL_ERROR "Must have working threads library for Long-range thread support")
     endif()
   endif()
   if(INTEL_LRT_MODE STREQUAL "C++11")
-    add_definitions(-DLMP_INTEL_USERLRT -DLMP_INTEL_LRT11)
+    target_compile_definitions(lammps PRIVATE -DLMP_INTEL_USERLRT -DLMP_INTEL_LRT11)
   endif()
 
   if(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
@@ -46,7 +46,7 @@ if(PKG_USER-INTEL)
   if(TBB_FOUND)
     target_link_libraries(lammps PRIVATE ${TBB_MALLOC_LIBRARIES})
   else()
-    add_definitions(-DLMP_INTEL_NO_TBB)
+    target_compile_definitions(lammps PRIVATE -DLMP_INTEL_NO_TBB)
     if(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
       message(WARNING "USER-INTEL with Intel compilers should use TBB malloc libraries")
     endif()
@@ -54,7 +54,7 @@ if(PKG_USER-INTEL)
 
   find_package(MKL QUIET)
   if(MKL_FOUND)
-    add_definitions(-DLMP_USE_MKL_RNG)
+    target_compile_definitions(lammps PRIVATE -DLMP_USE_MKL_RNG)
     target_link_libraries(lammps PRIVATE ${MKL_LIBRARIES})
   else()
     message(STATUS "Pair style dpd/intel will be faster with MKL libraries")
@@ -71,7 +71,7 @@ if(PKG_USER-INTEL)
     set(CMAKE_EXE_LINKER_FLAGS  "${CMAKE_EXE_LINKER_FLAGS} -xHost -qopenmp -qoffload")
     set(MIC_OPTIONS "-qoffload-option,mic,compiler,\"-fp-model fast=2 -mGLOB_default_function_attrs=\\\"gather_scatter_loop_unroll=4\\\"\"")
     add_compile_options(-xMIC-AVX512 -qoffload -fno-alias -ansi-alias -restrict -qoverride-limits ${MIC_OPTIONS})
-    add_definitions(-DLMP_INTEL_OFFLOAD)
+    target_compile_definitions(lammps PRIVATE -DLMP_INTEL_OFFLOAD)
   else()
     if(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
       include(CheckCXXCompilerFlag)
diff --git a/cmake/Modules/Packages/USER-NETCDF.cmake b/cmake/Modules/Packages/USER-NETCDF.cmake
index 8d62f5f7ec..2c12d2b799 100644
--- a/cmake/Modules/Packages/USER-NETCDF.cmake
+++ b/cmake/Modules/Packages/USER-NETCDF.cmake
@@ -11,14 +11,14 @@ if(PKG_USER-NETCDF)
   if(NETCDF_FOUND)
     include_directories(${NETCDF_INCLUDE_DIRS})
     target_link_libraries(lammps PRIVATE ${NETCDF_LIBRARIES})
-    add_definitions(-DLMP_HAS_NETCDF)
+    target_compile_definitions(lammps PRIVATE -DLMP_HAS_NETCDF)
   endif(NETCDF_FOUND)
 
   if(PNETCDF_FOUND)
     include_directories(${PNETCDF_INCLUDES})
     target_link_libraries(lammps PRIVATE ${PNETCDF_LIBRARIES})
-    add_definitions(-DLMP_HAS_PNETCDF)
+    target_compile_definitions(lammps PRIVATE -DLMP_HAS_PNETCDF)
   endif(PNETCDF_FOUND)
 
-  add_definitions(-DNC_64BIT_DATA=0x0020)
+  target_compile_definitions(lammps PRIVATE -DNC_64BIT_DATA=0x0020)
 endif()
diff --git a/cmake/Modules/Packages/USER-OMP.cmake b/cmake/Modules/Packages/USER-OMP.cmake
index 4b1a4b1571..91f0467a17 100644
--- a/cmake/Modules/Packages/USER-OMP.cmake
+++ b/cmake/Modules/Packages/USER-OMP.cmake
@@ -6,7 +6,7 @@ if(PKG_USER-OMP)
                          ${USER-OMP_SOURCES_DIR}/fix_nh_omp.cpp
                          ${USER-OMP_SOURCES_DIR}/fix_nh_sphere_omp.cpp
                          ${USER-OMP_SOURCES_DIR}/domain_omp.cpp)
-    add_definitions(-DLMP_USER_OMP)
+    target_compile_definitions(lammps PRIVATE -DLMP_USER_OMP)
     set_property(GLOBAL PROPERTY "OMP_SOURCES" "${USER-OMP_SOURCES}")
 
     # detects styles which have USER-OMP version
diff --git a/cmake/Modules/Packages/USER-PLUMED.cmake b/cmake/Modules/Packages/USER-PLUMED.cmake
index a6cd20adbb..cfd187ed9d 100644
--- a/cmake/Modules/Packages/USER-PLUMED.cmake
+++ b/cmake/Modules/Packages/USER-PLUMED.cmake
@@ -69,12 +69,12 @@ if(PKG_USER-PLUMED)
     set(PLUMED_INSTALL_DIR ${INSTALL_DIR})
     add_dependencies(lammps plumed_build)
     if(PLUMED_MODE STREQUAL "STATIC")
-      add_definitions(-D__PLUMED_WRAPPER_CXX=1)
+      target_compile_definitions(lammps PRIVATE -D__PLUMED_WRAPPER_CXX=1)
       target_link_libraries(lammps PRIVATE ${PLUMED_INSTALL_DIR}/lib/libplumed.a ${PLUMED_LINK_LIBS} ${CMAKE_DL_LIBS})
     elseif(PLUMED_MODE STREQUAL "SHARED")
       target_link_libraries(lammps PRIVATE ${PLUMED_INSTALL_DIR}/lib/libplumed${CMAKE_SHARED_LIBRARY_SUFFIX} ${PLUMED_INSTALL_DIR}/lib/libplumedKernel${CMAKE_SHARED_LIBRARY_SUFFIX} ${CMAKE_DL_LIBS})
     elseif(PLUMED_MODE STREQUAL "RUNTIME")
-      add_definitions(-D__PLUMED_HAS_DLOPEN=1 -D__PLUMED_DEFAULT_KERNEL=${PLUMED_INSTALL_DIR}/lib/libplumedKernel${CMAKE_SHARED_LIBRARY_SUFFIX})
+      target_compile_definitions(lammps PRIVATE -D__PLUMED_HAS_DLOPEN=1 -D__PLUMED_DEFAULT_KERNEL=${PLUMED_INSTALL_DIR}/lib/libplumedKernel${CMAKE_SHARED_LIBRARY_SUFFIX})
       target_link_libraries(lammps PRIVATE ${PLUMED_INSTALL_DIR}/lib/libplumedWrapper.a -rdynamic ${CMAKE_DL_LIBS})
     endif()
     set(PLUMED_INCLUDE_DIRS "${PLUMED_INSTALL_DIR}/include")
@@ -82,12 +82,12 @@ if(PKG_USER-PLUMED)
     find_package(PkgConfig REQUIRED)
     pkg_check_modules(PLUMED REQUIRED plumed)
     if(PLUMED_MODE STREQUAL "STATIC")
-      add_definitions(-D__PLUMED_WRAPPER_CXX=1)
+      target_compile_definitions(lammps PRIVATE -D__PLUMED_WRAPPER_CXX=1)
       include(${PLUMED_LIBDIR}/plumed/src/lib/Plumed.cmake.static)
     elseif(PLUMED_MODE STREQUAL "SHARED")
       include(${PLUMED_LIBDIR}/plumed/src/lib/Plumed.cmake.shared)
     elseif(PLUMED_MODE STREQUAL "RUNTIME")
-      add_definitions(-D__PLUMED_HAS_DLOPEN=1 -D__PLUMED_DEFAULT_KERNEL=${PLUMED_LIBDIR}/libplumedKernel${CMAKE_SHARED_LIBRARY_SUFFIX})
+      target_compile_definitions(lammps PRIVATE -D__PLUMED_HAS_DLOPEN=1 -D__PLUMED_DEFAULT_KERNEL=${PLUMED_LIBDIR}/libplumedKernel${CMAKE_SHARED_LIBRARY_SUFFIX})
       include(${PLUMED_LIBDIR}/plumed/src/lib/Plumed.cmake.runtime)
     endif()
     target_link_libraries(lammps PRIVATE ${PLUMED_LOAD})
diff --git a/cmake/Modules/Packages/USER-VTK.cmake b/cmake/Modules/Packages/USER-VTK.cmake
index fb69f115b2..61defcbf82 100644
--- a/cmake/Modules/Packages/USER-VTK.cmake
+++ b/cmake/Modules/Packages/USER-VTK.cmake
@@ -1,6 +1,6 @@
 if(PKG_USER-VTK)
   find_package(VTK REQUIRED NO_MODULE)
   include(${VTK_USE_FILE})
-  add_definitions(-DLAMMPS_VTK)
+  target_compile_definitions(lammps PRIVATE -DLAMMPS_VTK)
   target_link_libraries(lammps PRIVATE ${VTK_LIBRARIES})
 endif()