diff --git a/ports/grpc/00015-target-definitions.patch b/ports/grpc/00015-target-definitions.patch
new file mode 100644
index 00000000..a6bcb04e
--- /dev/null
+++ b/ports/grpc/00015-target-definitions.patch
@@ -0,0 +1,102 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 0097a1c..194d338 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -65,6 +65,8 @@ else()
+   set(_gRPC_INSTALL_SUPPORTED_FROM_MODULE ON)
+ endif()
+ 
++add_library(grpc_definitions INTERFACE)
++
+ # Providers for third-party dependencies (gRPC_*_PROVIDER properties):
+ # "module": build the dependency using sources from git submodule (under third_party)
+ # "package": use cmake's find_package functionality to locate a pre-installed dependency
+@@ -222,7 +224,7 @@ endif()
+ 
+ if(MSVC)
+   include(cmake/msvc_static_runtime.cmake)
+-  add_definitions(-D_WIN32_WINNT=0x600 -D_SCL_SECURE_NO_WARNINGS -D_CRT_SECURE_NO_WARNINGS -D_WINSOCK_DEPRECATED_NO_WARNINGS)
++  target_compile_definitions(grpc_definitions INTERFACE -D_WIN32_WINNT=0x600 -D_SCL_SECURE_NO_WARNINGS -D_CRT_SECURE_NO_WARNINGS -D_WINSOCK_DEPRECATED_NO_WARNINGS)
+   # needed to compile protobuf
+   set(_gRPC_C_CXX_FLAGS "${_gRPC_C_CXX_FLAGS} /wd4065 /wd4506")
+   # TODO(jtattermusch): revisit warnings that were silenced as part of upgrade to protobuf3.6.0
+@@ -232,24 +234,24 @@ if(MSVC)
+   # TODO(jtattermusch): needed to build boringssl with VS2017, revisit later
+   set(_gRPC_C_CXX_FLAGS "${_gRPC_C_CXX_FLAGS} /wd4987 /wd4774 /wd4819 /wd4996 /wd4619")
+   if(_gRPC_PLATFORM_UWP)
+-    add_definitions(-DGRPC_ARES=0)
++    target_compile_definitions(grpc_definitions INTERFACE -DGRPC_ARES=0)
+   endif()
+ endif()
+ if (MINGW)
+-  add_definitions(-D_WIN32_WINNT=0x600)
++  target_compile_definitions(grpc_definitions INTERFACE -D_WIN32_WINNT=0x600)
+ endif()
+ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_gRPC_C_CXX_FLAGS}")
+ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_gRPC_C_CXX_FLAGS}")
+ 
+ if(gRPC_USE_PROTO_LITE)
+   set(_gRPC_PROTOBUF_LIBRARY_NAME "libprotobuf-lite")
+-  add_definitions("-DGRPC_USE_PROTO_LITE")
++  target_compile_definitions(grpc_definitions INTERFACE -DGRPC_USE_PROTO_LITE)
+ else()
+   set(_gRPC_PROTOBUF_LIBRARY_NAME "libprotobuf")
+ endif()
+ 
+ if(gRPC_BACKWARDS_COMPATIBILITY_MODE)
+-  add_definitions(-DGPR_BACKWARDS_COMPATIBILITY_MODE)
++  target_compile_definitions(grpc_definitions INTERFACE -DGPR_BACKWARDS_COMPATIBILITY_MODE)
+   if(_gRPC_PLATFORM_MAC)
+     # some C++11 constructs not supported before OS X 10.10
+     set(CMAKE_OSX_DEPLOYMENT_TARGET 10.10)
+@@ -265,7 +267,7 @@ endif()
+ if (gRPC_XDS_USER_AGENT_IS_CSHARP)
+   # The value of the defines needs to contain quotes.
+   # See https://github.com/grpc/grpc/blob/fbf32836a418cc84f58786700273b65cb9174e1d/src/core/ext/xds/xds_api.cc#L854
+-  add_definitions("-DGRPC_XDS_USER_AGENT_NAME_SUFFIX=\"csharp\"" "-DGRPC_XDS_USER_AGENT_VERSION_SUFFIX=\"2.41.0\"")
++  target_compile_definitions(grpc_definitions INTERFACE "-DGRPC_XDS_USER_AGENT_NAME_SUFFIX=\"csharp\"" "-DGRPC_XDS_USER_AGENT_VERSION_SUFFIX=\"2.41.0\"")
+ endif()
+ 
+ include(cmake/abseil-cpp.cmake)
+@@ -285,15 +287,15 @@ if(ABSL_USE_CXX17)
+ endif()
+ 
+ if(_gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_IOS)
+-  set(_gRPC_ALLTARGETS_LIBRARIES ${CMAKE_DL_LIBS} m pthread)
++  set(_gRPC_ALLTARGETS_LIBRARIES ${CMAKE_DL_LIBS} m pthread grpc_definitions)
+ elseif(_gRPC_PLATFORM_ANDROID)
+-  set(_gRPC_ALLTARGETS_LIBRARIES ${CMAKE_DL_LIBS} m)
++  set(_gRPC_ALLTARGETS_LIBRARIES ${CMAKE_DL_LIBS} m grpc_definitions)
+ elseif(UNIX)
+-  set(_gRPC_ALLTARGETS_LIBRARIES ${CMAKE_DL_LIBS} rt m pthread)
++  set(_gRPC_ALLTARGETS_LIBRARIES ${CMAKE_DL_LIBS} rt m pthread grpc_definitions)
+ endif()
+ 
+ if(WIN32)
+-  set(_gRPC_BASELIB_LIBRARIES wsock32 ws2_32 crypt32 gdi32)
++  set(_gRPC_BASELIB_LIBRARIES wsock32 ws2_32 crypt32 gdi32 grpc_definitions)
+ endif()
+ 
+ # Create directory for generated .proto files
+@@ -1115,7 +1117,7 @@ target_link_libraries(address_sorting
+ 
+ 
+ if(gRPC_INSTALL)
+-  install(TARGETS address_sorting EXPORT gRPCTargets
++  install(TARGETS address_sorting grpc_definitions EXPORT gRPCTargets
+     RUNTIME DESTINATION ${gRPC_INSTALL_BINDIR}
+     LIBRARY DESTINATION ${gRPC_INSTALL_LIBDIR}
+     ARCHIVE DESTINATION ${gRPC_INSTALL_LIBDIR}
+diff --git a/cmake/abseil-cpp.cmake b/cmake/abseil-cpp.cmake
+index c625bad..2f216c8 100644
+--- a/cmake/abseil-cpp.cmake
++++ b/cmake/abseil-cpp.cmake
+@@ -34,7 +34,7 @@ elseif(gRPC_ABSL_PROVIDER STREQUAL "package")
+   # Use "CONFIG" as there is no built-in cmake module for absl.
+   find_package(absl REQUIRED CONFIG)
+   if (gRPC_ABSL_SYNC_ENABLE)
+-    add_definitions(-DGPR_ABSEIL_SYNC=1)
++    target_compile_definitions(grpc_definitions INTERFACE -DGPR_ABSEIL_SYNC=1)
+   endif()
+ endif()
+ set(_gRPC_FIND_ABSL "if(NOT TARGET absl::strings)\n  find_package(absl CONFIG)\nendif()")
diff --git a/ports/grpc/portfile.cmake b/ports/grpc/portfile.cmake
index b12c088e..fc22abd1 100644
--- a/ports/grpc/portfile.cmake
+++ b/ports/grpc/portfile.cmake
@@ -21,6 +21,7 @@ vcpkg_from_github(
         00012-fix-use-cxx17.patch
         00013-build-upbdefs.patch
         00014-pkgconfig-upbdefs.patch
+        00015-target-definitions.patch
 )
 
 if(NOT TARGET_TRIPLET STREQUAL HOST_TRIPLET)