Force define __STDC_FORMAT_MACROS for PRIdxx types
diff --git a/include/grpc/impl/codegen/port_platform.h b/include/grpc/impl/codegen/port_platform.h
index 0f4316c..baea4bc 100644
--- a/include/grpc/impl/codegen/port_platform.h
+++ b/include/grpc/impl/codegen/port_platform.h
@@ -415,4 +415,8 @@
 #endif /* GPR_ATTRIBUTE_NO_TSAN (2) */
 #endif /* GPR_ATTRIBUTE_NO_TSAN (1) */
 
+#ifndef __STDC_FORMAT_MACROS
+#define __STDC_FORMAT_MACROS
+#endif
+
 #endif /* GRPC_IMPL_CODEGEN_PORT_PLATFORM_H */