diff --git a/include/grpc/support/cpu.h b/include/grpc/support/cpu.h
index 863d5d2a224..db4bdd42aab 100644
--- a/include/grpc/support/cpu.h
+++ b/include/grpc/support/cpu.h
@@ -34,6 +34,8 @@
 #ifndef GRPC_SUPPORT_CPU_H
 #define GRPC_SUPPORT_CPU_H
 
+#include <grpc/support/port_platform.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/include/grpc/support/subprocess.h b/include/grpc/support/subprocess.h
index 2ccdfccc08c..ffbdf673577 100644
--- a/include/grpc/support/subprocess.h
+++ b/include/grpc/support/subprocess.h
@@ -34,6 +34,8 @@
 #ifndef GRPC_SUPPORT_SUBPROCESS_H
 #define GRPC_SUPPORT_SUBPROCESS_H
 
+#include <grpc/support/port_platform.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif