diff --git a/CMakeLists.txt b/CMakeLists.txt
index d3ebb5d1773..48d3d11d238 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -94,7 +94,7 @@ endif()
 
 set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
 
-add_definitions(-DPB_FIELD_16BIT)
+add_definitions(-DPB_FIELD_32BIT)
 
 if (MSVC)
   include(cmake/msvc_static_runtime.cmake)
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index f873bc693bc..240afbff7e6 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -93,7 +93,7 @@ Pod::Spec.new do |s|
   }
 
   s.default_subspecs = 'Interface', 'Implementation'
-  s.compiler_flags = '-DGRPC_ARES=0', '-DPB_FIELD_16BIT'
+  s.compiler_flags = '-DGRPC_ARES=0', '-DPB_FIELD_32BIT'
   s.libraries = 'c++'
 
   # Like many other C libraries, gRPC-Core has its public headers under `include/<libname>/` and its
diff --git a/setup.py b/setup.py
index 7bdfc99e24b..7f58e7ca070 100644
--- a/setup.py
+++ b/setup.py
@@ -160,7 +160,7 @@ if EXTRA_ENV_COMPILE_ARGS is None:
     EXTRA_ENV_COMPILE_ARGS += ' -std=gnu99 -fvisibility=hidden -fno-wrapv -fno-exceptions'
   elif "darwin" in sys.platform:
     EXTRA_ENV_COMPILE_ARGS += ' -fvisibility=hidden -fno-wrapv -fno-exceptions'
-EXTRA_ENV_COMPILE_ARGS += ' -DPB_FIELD_16BIT'
+EXTRA_ENV_COMPILE_ARGS += ' -DPB_FIELD_32BIT'
 
 if EXTRA_ENV_LINK_ARGS is None:
   EXTRA_ENV_LINK_ARGS = ''
diff --git a/templates/CMakeLists.txt.template b/templates/CMakeLists.txt.template
index 1628493d000..f33d980cd00 100644
--- a/templates/CMakeLists.txt.template
+++ b/templates/CMakeLists.txt.template
@@ -143,7 +143,7 @@
   ## Some libraries are shared even with BUILD_SHARED_LIBRARIES=OFF
   set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
   
-  add_definitions(-DPB_FIELD_16BIT)
+  add_definitions(-DPB_FIELD_32BIT)
 
   if (MSVC)
     include(cmake/msvc_static_runtime.cmake)
diff --git a/templates/gRPC-Core.podspec.template b/templates/gRPC-Core.podspec.template
index 461e8b767ff..5e6080448b2 100644
--- a/templates/gRPC-Core.podspec.template
+++ b/templates/gRPC-Core.podspec.template
@@ -152,7 +152,7 @@
     }
 
     s.default_subspecs = 'Interface', 'Implementation'
-    s.compiler_flags = '-DGRPC_ARES=0', '-DPB_FIELD_16BIT'
+    s.compiler_flags = '-DGRPC_ARES=0', '-DPB_FIELD_32BIT'
     s.libraries = 'c++'
 
     # Like many other C libraries, gRPC-Core has its public headers under `include/<libname>/` and its