diff --git a/include/grpc/impl/codegen/port_platform.h b/include/grpc/impl/codegen/port_platform.h
index 1aeda9b658a418887554ea255eba0a97976cbfef..f65f56db87dcc499b3f4eb61d8f553cbf390bf34 100644
--- a/include/grpc/impl/codegen/port_platform.h
+++ b/include/grpc/impl/codegen/port_platform.h
@@ -178,8 +178,8 @@
 #define GPR_LINUX_LOG
 #define GPR_SUPPORT_CHANNELS_FROM_FD 1
 #define GPR_LINUX_ENV 1
-#ifndef GPR_LINUX_EVENTFD
-#define GPR_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#ifndef GRPC_LINUX_EVENTFD
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
 #endif
 #define GPR_POSIX_FILE 1
 #define GPR_POSIX_TMPFILE 1
@@ -348,10 +348,6 @@ typedef unsigned __int64 uint64_t;
 #error Must define exactly one of GPR_CPU_LINUX, GPR_CPU_POSIX, GPR_WINDOWS, GPR_CPU_IPHONE, GPR_CPU_CUSTOM
 #endif
 
-#if defined(GPR_POSIX_MULTIPOLL_WITH_POLL) && !defined(GPR_POSIX_SOCKET)
-#error Must define GPR_POSIX_SOCKET to use GPR_POSIX_MULTIPOLL_WITH_POLL
-#endif
-
 #if defined(GPR_MSVC_TLS) + defined(GPR_GCC_TLS) + defined(GPR_PTHREAD_TLS) + \
         defined(GPR_CUSTOM_TLS) !=                                            \
     1
diff --git a/src/core/ext/client_config/parse_address.c b/src/core/ext/client_config/parse_address.c
index 8b4abe24a6118f752ddc2cd0ff7c626ddb0e2e06..7c548b15adbb3f771a9c91331ded509bc9dbcffe 100644
--- a/src/core/ext/client_config/parse_address.c
+++ b/src/core/ext/client_config/parse_address.c
@@ -35,7 +35,7 @@
 
 #include <stdio.h>
 #include <string.h>
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
 #include <sys/un.h>
 #endif
 
@@ -44,7 +44,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
 int parse_unix(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len) {
   struct sockaddr_un *un = (struct sockaddr_un *)addr;
 
diff --git a/src/core/ext/client_config/parse_address.h b/src/core/ext/client_config/parse_address.h
index 74c86f4d938b97d2cebf01f28e413d94e0ca12c1..16300de20871c9cfddc0e229256b462016c22b5d 100644
--- a/src/core/ext/client_config/parse_address.h
+++ b/src/core/ext/client_config/parse_address.h
@@ -39,7 +39,7 @@
 #include "src/core/ext/client_config/uri_parser.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
 /** Populate \a addr and \a len from \a uri, whose path is expected to contain a
  * unix socket path. Returns true upon success. */
 int parse_unix(grpc_uri *uri, struct sockaddr_storage *addr, size_t *len);
diff --git a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
index 1f7cce2f43a9a14976b4330143d5bdcfeb9226c9..d613c5393e05b9aa68dbe70d03747cd534c9b601 100644
--- a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
+++ b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
@@ -163,7 +163,7 @@ static char *ipv6_get_default_authority(grpc_resolver_factory *factory,
   return ip_get_default_authority(uri);
 }
 
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
 char *unix_get_default_authority(grpc_resolver_factory *factory,
                                  grpc_uri *uri) {
   return gpr_strdup("localhost");
@@ -271,7 +271,7 @@ static void sockaddr_factory_unref(grpc_resolver_factory *factory) {}
   static grpc_resolver_factory name##_resolver_factory = {                  \
       &name##_factory_vtable}
 
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
 DECL_FACTORY(unix);
 #endif
 DECL_FACTORY(ipv4);
@@ -280,7 +280,7 @@ DECL_FACTORY(ipv6);
 void grpc_resolver_sockaddr_init(void) {
   grpc_register_resolver_type(&ipv4_resolver_factory);
   grpc_register_resolver_type(&ipv6_resolver_factory);
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
   grpc_register_resolver_type(&unix_resolver_factory);
 #endif
 }
diff --git a/src/core/lib/iomgr/endpoint_pair_posix.c b/src/core/lib/iomgr/endpoint_pair_posix.c
index 7437dbf6abc4d848b9417a4ce27f0fc88b92f172..ec2cd782b144721f97b4b6eafb69cfcc2d2cb409 100644
--- a/src/core/lib/iomgr/endpoint_pair_posix.c
+++ b/src/core/lib/iomgr/endpoint_pair_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/endpoint_pair.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
diff --git a/src/core/lib/iomgr/endpoint_pair_windows.c b/src/core/lib/iomgr/endpoint_pair_windows.c
index 0933ba0d570e7ee371498bacff1695d6e2116434..5c78c95492ba4f5f48c4c0ba0a52df9410e224d1 100644
--- a/src/core/lib/iomgr/endpoint_pair_windows.c
+++ b/src/core/lib/iomgr/endpoint_pair_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 #include "src/core/lib/iomgr/endpoint_pair.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
index 2d9c0e49b29667779c918e962695d2680c9b84c6..9837a98692894da943bd6ebaedb227084115e6b2 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -35,7 +35,7 @@
 #include "src/core/lib/iomgr/port.h"
 
 /* This polling engine is only relevant on linux kernels supporting epoll() */
-#ifdef GPR_LINUX_EPOLL
+#ifdef GRPC_LINUX_EPOLL
 
 #include "src/core/lib/iomgr/ev_epoll_linux.h"
 
@@ -1905,13 +1905,13 @@ const grpc_event_engine_vtable *grpc_init_epoll_linux(void) {
   return &vtable;
 }
 
-#else /* defined(GPR_LINUX_EPOLL) */
-#if defined(GPR_POSIX_SOCKET)
+#else /* defined(GRPC_LINUX_EPOLL) */
+#if defined(GRPC_POSIX_SOCKET)
 #include "src/core/lib/iomgr/ev_posix.h"
-/* If GPR_LINUX_EPOLL is not defined, it means epoll is not available. Return
+/* If GRPC_LINUX_EPOLL is not defined, it means epoll is not available. Return
  * NULL */
 const grpc_event_engine_vtable *grpc_init_epoll_linux(void) { return NULL; }
-#endif /* defined(GPR_POSIX_SOCKET) */
+#endif /* defined(GRPC_POSIX_SOCKET) */
 
 void grpc_use_signal(int signum) {}
-#endif /* !defined(GPR_LINUX_EPOLL) */
+#endif /* !defined(GRPC_LINUX_EPOLL) */
diff --git a/src/core/lib/iomgr/ev_epoll_linux.h b/src/core/lib/iomgr/ev_epoll_linux.h
index e2a66555bcdaa68a97d140a931af2a844c562e07..e6d5441236b37a09b3933b26647738e2d414ea9e 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.h
+++ b/src/core/lib/iomgr/ev_epoll_linux.h
@@ -39,10 +39,10 @@
 
 const grpc_event_engine_vtable *grpc_init_epoll_linux(void);
 
-#ifdef GPR_LINUX_EPOLL
+#ifdef GRPC_LINUX_EPOLL
 void *grpc_fd_get_polling_island(grpc_fd *fd);
 void *grpc_pollset_get_polling_island(grpc_pollset *ps);
 bool grpc_are_polling_islands_equal(void *p, void *q);
-#endif /* defined(GPR_LINUX_EPOLL) */
+#endif /* defined(GRPC_LINUX_EPOLL) */
 
 #endif /* GRPC_CORE_LIB_IOMGR_EV_EPOLL_LINUX_H */
diff --git a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
index 57ae8325e8ebe23b7eb1f99380d82866759d32c8..fb35311d2b3f601eee446d2a8ae9e8065b1aca77 100644
--- a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
@@ -44,7 +44,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/ev_poll_and_epoll_posix.h"
 
@@ -1338,7 +1338,7 @@ static void become_basic_pollset(grpc_pollset *pollset, grpc_fd *fd_or_null) {
  * pollset_multipoller_with_poll_posix.c
  */
 
-#ifndef GPR_LINUX_MULTIPOLL_WITH_EPOLL
+#ifndef GRPC_LINUX_MULTIPOLL_WITH_EPOLL
 
 typedef struct {
   /* all polled fds */
@@ -1520,13 +1520,13 @@ static void poll_become_multipoller(grpc_exec_ctx *exec_ctx,
   }
 }
 
-#endif /* !GPR_LINUX_MULTIPOLL_WITH_EPOLL */
+#endif /* !GRPC_LINUX_MULTIPOLL_WITH_EPOLL */
 
 /*******************************************************************************
  * pollset_multipoller_with_epoll_posix.c
  */
 
-#ifdef GPR_LINUX_MULTIPOLL_WITH_EPOLL
+#ifdef GRPC_LINUX_MULTIPOLL_WITH_EPOLL
 
 #include <errno.h>
 #include <poll.h>
@@ -1839,11 +1839,11 @@ static void epoll_become_multipoller(grpc_exec_ctx *exec_ctx,
   }
 }
 
-#else /* GPR_LINUX_MULTIPOLL_WITH_EPOLL */
+#else /* GRPC_LINUX_MULTIPOLL_WITH_EPOLL */
 
 static void remove_fd_from_all_epoll_sets(int fd) {}
 
-#endif /* GPR_LINUX_MULTIPOLL_WITH_EPOLL */
+#endif /* GRPC_LINUX_MULTIPOLL_WITH_EPOLL */
 
 /*******************************************************************************
  * pollset_set_posix.c
@@ -2033,7 +2033,7 @@ static const grpc_event_engine_vtable vtable = {
 };
 
 const grpc_event_engine_vtable *grpc_init_poll_and_epoll_posix(void) {
-#ifdef GPR_LINUX_MULTIPOLL_WITH_EPOLL
+#ifdef GRPC_LINUX_MULTIPOLL_WITH_EPOLL
   platform_become_multipoller = epoll_become_multipoller;
 #else
   platform_become_multipoller = poll_become_multipoller;
diff --git a/src/core/lib/iomgr/ev_poll_posix.c b/src/core/lib/iomgr/ev_poll_posix.c
index 7df1b2e3de2c9d3ca3cc146b155620b3f2aba213..52c137b8a33d11077d221b3a2e56d4a30bc7fa83 100644
--- a/src/core/lib/iomgr/ev_poll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/ev_poll_posix.h"
 
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
index b510c6fc26d94523d1a7f43cab62f431e305c316..6079a60b22f05a94424865d89bb3b3b39da8c7fe 100644
--- a/src/core/lib/iomgr/ev_posix.c
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/ev_posix.h"
 
@@ -258,4 +258,4 @@ void grpc_pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
 
 grpc_error *grpc_kick_poller(void) { return g_event_engine->kick_poller(); }
 
-#endif  // GPR_POSIX_SOCKET
+#endif  // GRPC_POSIX_SOCKET
diff --git a/src/core/lib/iomgr/iocp_windows.c b/src/core/lib/iomgr/iocp_windows.c
index e6915502a43595f53709710f4dd85043a2b1e93d..60ebe43676dce3b8c4d2549a3003ec6700a91ecf 100644
--- a/src/core/lib/iomgr/iocp_windows.c
+++ b/src/core/lib/iomgr/iocp_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include <winsock2.h>
 
@@ -166,4 +166,4 @@ void grpc_iocp_add_socket(grpc_winsocket *socket) {
   GPR_ASSERT(ret == g_iocp);
 }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/iomgr_posix.c b/src/core/lib/iomgr/iomgr_posix.c
index 963684ad7ae941a57bc08d146910afcd120b46e8..f5ee0c9ee4e732c8303e6c6cfb3a9f8d834313af 100644
--- a/src/core/lib/iomgr/iomgr_posix.c
+++ b/src/core/lib/iomgr/iomgr_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/iomgr/ev_posix.h"
diff --git a/src/core/lib/iomgr/iomgr_windows.c b/src/core/lib/iomgr/iomgr_windows.c
index e0e307bf814abda989f2aa4330ca206403eab34c..b659264edef35d97a6575dc468d9a8a792f8bc77 100644
--- a/src/core/lib/iomgr/iomgr_windows.c
+++ b/src/core/lib/iomgr/iomgr_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include "src/core/lib/iomgr/sockaddr_windows.h"
 
diff --git a/src/core/lib/iomgr/pollset_set_windows.c b/src/core/lib/iomgr/pollset_set_windows.c
index 4a2563d32efca6a6b1e7aa9ff44f375644906a43..293893f18eb2282b4516a7eb0c8835fcb524353e 100644
--- a/src/core/lib/iomgr/pollset_set_windows.c
+++ b/src/core/lib/iomgr/pollset_set_windows.c
@@ -34,7 +34,7 @@
 #include "src/core/lib/iomgr/port.h"
 #include <stdint.h>
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include "src/core/lib/iomgr/pollset_set_windows.h"
 
@@ -60,4 +60,4 @@ void grpc_pollset_set_del_pollset_set(grpc_exec_ctx* exec_ctx,
                                       grpc_pollset_set* bag,
                                       grpc_pollset_set* item) {}
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/pollset_windows.c b/src/core/lib/iomgr/pollset_windows.c
index bd650d56091806c667240356a625c648fd31d040..5540303e49ba4413f67e30fa3476d10463fde25c 100644
--- a/src/core/lib/iomgr/pollset_windows.c
+++ b/src/core/lib/iomgr/pollset_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include <grpc/support/log.h>
 #include <grpc/support/thd.h>
@@ -241,4 +241,4 @@ grpc_error *grpc_pollset_kick(grpc_pollset *p,
 
 void grpc_kick_poller(void) { grpc_iocp_kick(); }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/port.h b/src/core/lib/iomgr/port.h
index acd68dce79d926fb38210825be0fa92f5d8beade..021bbfff5abafb5c53b733594919dbe2b8cd533e 100644
--- a/src/core/lib/iomgr/port.h
+++ b/src/core/lib/iomgr/port.h
@@ -37,88 +37,86 @@
 #define GRPC_CORE_LIB_IOMGR_PORT_H
 
 #if defined(GPR_WINDOWS)
-#define GPR_WINSOCK_SOCKET 1
-#define GPR_WINDOWS_SOCKETUTILS 1
-/* #undef GPR_POSIX_SOCKET */
-/* #undef GPR_POSIX_WAKEUP_FD */
+#define GRPC_WINSOCK_SOCKET 1
+#define GRPC_WINDOWS_SOCKETUTILS 1
 #elif defined(GPR_MANYLINUX1)
-#define GPR_HAVE_IPV6_RECVPKTINFO 1
-#define GPR_HAVE_IP_PKTINFO 1
-#define GPR_HAVE_MSG_NOSIGNAL 1
-#define GPR_HAVE_UNIX_SOCKET 1
-#define GPR_POSIX_NO_SPECIAL_WAKEUP_FD 1
-#define GPR_POSIX_SOCKET 1
-#define GPR_POSIX_SOCKETADDR 1
-#define GPR_POSIX_SOCKETUTILS 1
-#define GPR_POSIX_WAKEUP_FD 1
+#define GRPC_HAVE_IPV6_RECVPKTINFO 1
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_MSG_NOSIGNAL 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
 #elif defined(GPR_ANDROID)
-#define GPR_HAVE_IPV6_RECVPKTINFO 1
-#define GPR_HAVE_IP_PKTINFO 1
-#define GPR_HAVE_MSG_NOSIGNAL 1
-#define GPR_HAVE_UNIX_SOCKET 1
-#define GPR_LINUX_EVENTFD 1
-#define GPR_POSIX_SOCKET 1
-#define GPR_POSIX_SOCKETADDR 1
-#define GPR_POSIX_SOCKETUTILS 1
-#define GPR_POSIX_WAKEUP_FD 1
+#define GRPC_HAVE_IPV6_RECVPKTINFO 1
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_MSG_NOSIGNAL 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_LINUX_EVENTFD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
 #elif defined(GPR_LINUX)
-#define GPR_HAVE_IPV6_RECVPKTINFO 1
-#define GPR_HAVE_IP_PKTINFO 1
-#define GPR_HAVE_MSG_NOSIGNAL 1
-#define GPR_HAVE_UNIX_SOCKET 1
-#define GPR_LINUX_MULTIPOLL_WITH_EPOLL 1
-#define GPR_POSIX_SOCKET 1
-#define GPR_POSIX_SOCKETADDR 1
-#define GPR_POSIX_WAKEUP_FD 1
+#define GRPC_HAVE_IPV6_RECVPKTINFO 1
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_MSG_NOSIGNAL 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_LINUX_MULTIPOLL_WITH_EPOLL 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_WAKEUP_FD 1
 #ifdef __GLIBC_PREREQ
 #if __GLIBC_PREREQ(2, 9)
-#define GPR_LINUX_EPOLL 1
-#define GPR_LINUX_EVENTFD 1
+#define GRPC_LINUX_EPOLL 1
+#define GRPC_LINUX_EVENTFD 1
 #endif
 #if __GLIBC_PREREQ(2, 10)
-#define GPR_LINUX_SOCKETUTILS 1
+#define GRPC_LINUX_SOCKETUTILS 1
 #endif
 #endif
-#ifndef GPR_LINUX_EVENTFD
-#define GPR_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#ifndef GRPC_LINUX_EVENTFD
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
 #endif
-#ifndef GPR_LINUX_SOCKETUTILS
-#define GPR_POSIX_SOCKETUTILS
+#ifndef GRPC_LINUX_SOCKETUTILS
+#define GRPC_POSIX_SOCKETUTILS
 #endif
 #elif defined(GPR_APPLE)
-#define GPR_HAVE_IP_PKTINFO 1
-#define GPR_HAVE_SO_NOSIGPIPE 1
-#define GPR_HAVE_UNIX_SOCKET 1
-#define GPR_MSG_IOVLEN_TYPE int
-#define GPR_POSIX_NO_SPECIAL_WAKEUP_FD 1
-#define GPR_POSIX_SOCKET 1
-#define GPR_POSIX_SOCKETADDR 1
-#define GPR_POSIX_SOCKETUTILS 1
-#define GPR_POSIX_WAKEUP_FD 1
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_SO_NOSIGPIPE 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_MSG_IOVLEN_TYPE int
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
 #elif defined(GPR_FREEBSD)
-#define GPR_HAVE_IPV6_RECVPKTINFO 1
-#define GPR_HAVE_IP_PKTINFO 1
-#define GPR_HAVE_SO_NOSIGPIPE 1
-#define GPR_HAVE_UNIX_SOCKET 1
-#define GPR_POSIX_NO_SPECIAL_WAKEUP_FD 1
-#define GPR_POSIX_SOCKET 1
-#define GPR_POSIX_SOCKETADDR 1
-#define GPR_POSIX_SOCKETUTILS 1
-#define GPR_POSIX_WAKEUP_FD 1
+#define GRPC_HAVE_IPV6_RECVPKTINFO 1
+#define GRPC_HAVE_IP_PKTINFO 1
+#define GRPC_HAVE_SO_NOSIGPIPE 1
+#define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
 #elif defined(GPR_NACL)
-#define GPR_POSIX_NO_SPECIAL_WAKEUP_FD 1
-#define GPR_POSIX_SOCKET 1
-#define GPR_POSIX_SOCKETADDR 1
-#define GPR_POSIX_SOCKETUTILS 1
-#define GPR_POSIX_WAKEUP_FD 1
+#define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
+#define GRPC_POSIX_SOCKET 1
+#define GRPC_POSIX_SOCKETADDR 1
+#define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_WAKEUP_FD 1
 #elif !defined(GPR_NO_AUTODETECT_PLATFORM)
 #error "Platform not recognized"
 #endif
 
-#if defined(GPR_POSIX_SOCKET) + defined(GPR_WINSOCK_SOCKET) + \
-        defined(GPR_CUSTOM_SOCKET) !=                         \
+#if defined(GRPC_POSIX_SOCKET) + defined(GRPC_WINSOCK_SOCKET) + \
+        defined(GRPC_CUSTOM_SOCKET) !=                          \
     1
-#error Must define exactly one of GPR_POSIX_SOCKET, GPR_WINSOCK_SOCKET, GPR_CUSTOM_SOCKET
+#error Must define exactly one of GRPC_POSIX_SOCKET, GRPC_WINSOCK_SOCKET, GPR_CUSTOM_SOCKET
 #endif
 
 #endif  /* GRPC_CORE_LIB_IOMGR_PORT_H */
diff --git a/src/core/lib/iomgr/resolve_address_posix.c b/src/core/lib/iomgr/resolve_address_posix.c
index 164fe10855ee907c8c25556524bfa08de04d5cbd..9bc46901b11b9028fed36f78d57ab21379755e14 100644
--- a/src/core/lib/iomgr/resolve_address_posix.c
+++ b/src/core/lib/iomgr/resolve_address_posix.c
@@ -32,7 +32,7 @@
  */
 
 #include "src/core/lib/iomgr/port.h"
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/sockaddr.h"
diff --git a/src/core/lib/iomgr/resolve_address_windows.c b/src/core/lib/iomgr/resolve_address_windows.c
index 334473c6bf12b71c4c1ba00dd6a83448a39dc08b..460bd1f2ee324f5613168a70ace761a064ce383b 100644
--- a/src/core/lib/iomgr/resolve_address_windows.c
+++ b/src/core/lib/iomgr/resolve_address_windows.c
@@ -32,7 +32,7 @@
  */
 
 #include "src/core/lib/iomgr/port.h"
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/sockaddr.h"
diff --git a/src/core/lib/iomgr/sockaddr.h b/src/core/lib/iomgr/sockaddr.h
index fd85f176dab52be666e8e0b9e292298effe1f600..58cae6cc010b2bce2277783fa1bc823c580f5e6d 100644
--- a/src/core/lib/iomgr/sockaddr.h
+++ b/src/core/lib/iomgr/sockaddr.h
@@ -40,7 +40,7 @@
 #include "src/core/lib/iomgr/sockaddr_windows.h"
 #endif
 
-#ifdef GPR_POSIX_SOCKETADDR
+#ifdef GRPC_POSIX_SOCKETADDR
 #include "src/core/lib/iomgr/sockaddr_posix.h"
 #endif
 
diff --git a/src/core/lib/iomgr/socket_utils.h b/src/core/lib/iomgr/socket_utils.h
index 1d871a34e6d0ec91bac91575191cd320424b2a73..f0b5a33b638524ea8449c2bdfb459ca35ada77b8 100644
--- a/src/core/lib/iomgr/socket_utils.h
+++ b/src/core/lib/iomgr/socket_utils.h
@@ -36,7 +36,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 #include "sockaddr_windows.h"
 #else
 #include "sockaddr_posix.h"
diff --git a/src/core/lib/iomgr/socket_utils_common_posix.c b/src/core/lib/iomgr/socket_utils_common_posix.c
index afd9a7652e6175c1b8a4582cf42947c2c76e3c46..214325684658848beeb66ee7aceea94d9e1dd971 100644
--- a/src/core/lib/iomgr/socket_utils_common_posix.c
+++ b/src/core/lib/iomgr/socket_utils_common_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/socket_utils.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
@@ -79,7 +79,7 @@ grpc_error *grpc_set_socket_nonblocking(int fd, int non_blocking) {
 }
 
 grpc_error *grpc_set_socket_no_sigpipe_if_possible(int fd) {
-#ifdef GPR_HAVE_SO_NOSIGPIPE
+#ifdef GRPC_HAVE_SO_NOSIGPIPE
   int val = 1;
   int newval;
   socklen_t intlen = sizeof(newval);
@@ -97,7 +97,7 @@ grpc_error *grpc_set_socket_no_sigpipe_if_possible(int fd) {
 }
 
 grpc_error *grpc_set_socket_ip_pktinfo_if_possible(int fd) {
-#ifdef GPR_HAVE_IP_PKTINFO
+#ifdef GRPC_HAVE_IP_PKTINFO
   int get_local_ip = 1;
   if (0 != setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &get_local_ip,
                       sizeof(get_local_ip))) {
@@ -108,7 +108,7 @@ grpc_error *grpc_set_socket_ip_pktinfo_if_possible(int fd) {
 }
 
 grpc_error *grpc_set_socket_ipv6_recvpktinfo_if_possible(int fd) {
-#ifdef GPR_HAVE_IPV6_RECVPKTINFO
+#ifdef GRPC_HAVE_IPV6_RECVPKTINFO
   int get_local_ip = 1;
   if (0 != setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &get_local_ip,
                       sizeof(get_local_ip))) {
diff --git a/src/core/lib/iomgr/socket_utils_linux.c b/src/core/lib/iomgr/socket_utils_linux.c
index defdaf388e3455fe1b9cfd90a3225dfbf38a2d34..3ebc3f1ac1c599dbae87508a7d92e5facf07086e 100644
--- a/src/core/lib/iomgr/socket_utils_linux.c
+++ b/src/core/lib/iomgr/socket_utils_linux.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_LINUX_SOCKETUTILS
+#ifdef GRPC_LINUX_SOCKETUTILS
 
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 
diff --git a/src/core/lib/iomgr/socket_utils_posix.c b/src/core/lib/iomgr/socket_utils_posix.c
index a923ff870ff505fce0068c02aa6c204b49b6cd20..4f26773342a85dc7532fccbbf4dc7e13abda5dbf 100644
--- a/src/core/lib/iomgr/socket_utils_posix.c
+++ b/src/core/lib/iomgr/socket_utils_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKETUTILS
+#ifdef GRPC_POSIX_SOCKETUTILS
 
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 
@@ -67,4 +67,4 @@ close_and_error:
   return -1;
 }
 
-#endif /* GPR_POSIX_SOCKETUTILS */
+#endif /* GRPC_POSIX_SOCKETUTILS */
diff --git a/src/core/lib/iomgr/socket_utils_windows.c b/src/core/lib/iomgr/socket_utils_windows.c
index c9ddce156b89026626c172604458cfc1a5f153dd..74dbd57c7d4292ec1ed9345a11630e6c127532d4 100644
--- a/src/core/lib/iomgr/socket_utils_windows.c
+++ b/src/core/lib/iomgr/socket_utils_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINDOWS_SOCKETUTILS
+#ifdef GRPC_WINDOWS_SOCKETUTILS
 
 #include "src/core/lib/iomgr/socket_utils.h"
 
@@ -45,4 +45,4 @@ const char *grpc_inet_ntop(int af, const void *src,
   return InetNtop(af, src, dst, (size_t)size);
 }
 
-#endif /* GPR_WINDOWS_SOCKETUTILS */
+#endif /* GRPC_WINDOWS_SOCKETUTILS */
diff --git a/src/core/lib/iomgr/socket_windows.c b/src/core/lib/iomgr/socket_windows.c
index e9d0cedce558f4c1f0b0586ac9474ba17968f824..14bd603d02a8e2facf7f12456561953a4b2542a8 100644
--- a/src/core/lib/iomgr/socket_windows.c
+++ b/src/core/lib/iomgr/socket_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include <winsock2.h>
 
@@ -156,4 +156,4 @@ void grpc_socket_become_ready(grpc_exec_ctx *exec_ctx, grpc_winsocket *socket,
   if (should_destroy) destroy(socket);
 }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/tcp_client_posix.c b/src/core/lib/iomgr/tcp_client_posix.c
index 84b22d0c3331168a126a21cf96e03a69f20155c5..4c1dcd671fa5f42d5f11fd0b312e12ad14109b3e 100644
--- a/src/core/lib/iomgr/tcp_client_posix.c
+++ b/src/core/lib/iomgr/tcp_client_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/tcp_client.h"
 
diff --git a/src/core/lib/iomgr/tcp_client_windows.c b/src/core/lib/iomgr/tcp_client_windows.c
index 2ae4834f995b541e4a171a76d6c083261681a6c2..29775cce215c8d0f38b0cdd302c4fed7840e6a8d 100644
--- a/src/core/lib/iomgr/tcp_client_windows.c
+++ b/src/core/lib/iomgr/tcp_client_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include "src/core/lib/iomgr/sockaddr_windows.h"
 
@@ -228,4 +228,4 @@ failure:
   grpc_exec_ctx_sched(exec_ctx, on_done, final_error, NULL);
 }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index ba4dc7557532aac42bf8892d609c6bdf3eeb772d..b3ed0484fdf4633525fb0ca643cfc8ce2926bfbc 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/network_status_tracker.h"
 #include "src/core/lib/iomgr/tcp_posix.h"
@@ -58,14 +58,14 @@
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/string.h"
 
-#ifdef GPR_HAVE_MSG_NOSIGNAL
+#ifdef GRPC_HAVE_MSG_NOSIGNAL
 #define SENDMSG_FLAGS MSG_NOSIGNAL
 #else
 #define SENDMSG_FLAGS 0
 #endif
 
-#ifdef GPR_MSG_IOVLEN_TYPE
-typedef GPR_MSG_IOVLEN_TYPE msg_iovlen_type;
+#ifdef GRPC_MSG_IOVLEN_TYPE
+typedef GRPC_MSG_IOVLEN_TYPE msg_iovlen_type;
 #else
 typedef size_t msg_iovlen_type;
 #endif
diff --git a/src/core/lib/iomgr/tcp_server_posix.c b/src/core/lib/iomgr/tcp_server_posix.c
index 75241bd65de2e72a964b3f0241c9d23bab406be3..0a2c80a6f6f0493774210a83798922ebc6eb4119 100644
--- a/src/core/lib/iomgr/tcp_server_posix.c
+++ b/src/core/lib/iomgr/tcp_server_posix.c
@@ -38,7 +38,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/tcp_server.h"
 
diff --git a/src/core/lib/iomgr/tcp_server_windows.c b/src/core/lib/iomgr/tcp_server_windows.c
index fd193c3fa26bb7c7b0991f5bb3f71b2f9a595bf8..b84a1095371753497349800e9c65d37d080d3eda 100644
--- a/src/core/lib/iomgr/tcp_server_windows.c
+++ b/src/core/lib/iomgr/tcp_server_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include <io.h>
 
@@ -543,4 +543,4 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
 void grpc_tcp_server_shutdown_listeners(grpc_exec_ctx *exec_ctx,
                                         grpc_tcp_server *s) {}
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index 0eecccb0000db659fe4eedb29ba70652c7a6097b..533f07abc07f6500924bc902328216eb34b02ff7 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_WINSOCK_SOCKET
+#ifdef GRPC_WINSOCK_SOCKET
 
 #include <limits.h>
 
@@ -416,4 +416,4 @@ grpc_endpoint *grpc_tcp_create(grpc_winsocket *socket, char *peer_string) {
   return &tcp->base;
 }
 
-#endif /* GPR_WINSOCK_SOCKET */
+#endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/udp_server.c b/src/core/lib/iomgr/udp_server.c
index 07eee75e5a9b5a9a9dbc13b60cc45191f03d0057..b8076c965cdd7cb42fb5fa14c64f3c46efaecbcb 100644
--- a/src/core/lib/iomgr/udp_server.c
+++ b/src/core/lib/iomgr/udp_server.c
@@ -39,7 +39,7 @@
 #include "src/core/lib/iomgr/port.h"
 
 #ifdef GRPC_NEED_UDP
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/udp_server.h"
 
diff --git a/src/core/lib/iomgr/unix_sockets_posix.c b/src/core/lib/iomgr/unix_sockets_posix.c
index c59d38848b37fe048d2d0708e9ac70b55fd6093e..33082a2e9986535212afc91d5c5cee573f84860b 100644
--- a/src/core/lib/iomgr/unix_sockets_posix.c
+++ b/src/core/lib/iomgr/unix_sockets_posix.c
@@ -32,7 +32,7 @@
  */
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_HAVE_UNIX_SOCKET
+#ifdef GRPC_HAVE_UNIX_SOCKET
 
 #include <string.h>
 #include <sys/stat.h>
diff --git a/src/core/lib/iomgr/unix_sockets_posix_noop.c b/src/core/lib/iomgr/unix_sockets_posix_noop.c
index 56b47c3daf0ccfdd1f081c28d6b013d967a03f05..82f008d599a20c41a2e8233e80ba31bf7ebf7bfc 100644
--- a/src/core/lib/iomgr/unix_sockets_posix_noop.c
+++ b/src/core/lib/iomgr/unix_sockets_posix_noop.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
 
-#ifndef GPR_HAVE_UNIX_SOCKET
+#ifndef GRPC_HAVE_UNIX_SOCKET
 
 #include <grpc/support/log.h>
 
diff --git a/src/core/lib/iomgr/wakeup_fd_eventfd.c b/src/core/lib/iomgr/wakeup_fd_eventfd.c
index 3d21d9d1d5788ead9f2ce5069510d08ae9f7a768..373e21d3e157d528414f5b243298f08d02d42fcc 100644
--- a/src/core/lib/iomgr/wakeup_fd_eventfd.c
+++ b/src/core/lib/iomgr/wakeup_fd_eventfd.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_LINUX_EVENTFD
+#ifdef GRPC_LINUX_EVENTFD
 
 #include <errno.h>
 #include <sys/eventfd.h>
@@ -94,4 +94,4 @@ const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable = {
     eventfd_create, eventfd_consume, eventfd_wakeup, eventfd_destroy,
     eventfd_check_availability};
 
-#endif /* GPR_LINUX_EVENTFD */
+#endif /* GRPC_LINUX_EVENTFD */
diff --git a/src/core/lib/iomgr/wakeup_fd_nospecial.c b/src/core/lib/iomgr/wakeup_fd_nospecial.c
index c2b273d3a60b899a9da2df25dd75f4b73596ae74..611bced0291ef32ece6aec6287ae3fa80514fa23 100644
--- a/src/core/lib/iomgr/wakeup_fd_nospecial.c
+++ b/src/core/lib/iomgr/wakeup_fd_nospecial.c
@@ -38,7 +38,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_NO_SPECIAL_WAKEUP_FD
+#ifdef GRPC_POSIX_NO_SPECIAL_WAKEUP_FD
 
 #include <stddef.h>
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
@@ -48,4 +48,4 @@ static int check_availability_invalid(void) { return 0; }
 const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable = {
     NULL, NULL, NULL, NULL, check_availability_invalid};
 
-#endif /* GPR_POSIX_NO_SPECIAL_WAKEUP_FD */
+#endif /* GRPC_POSIX_NO_SPECIAL_WAKEUP_FD */
diff --git a/src/core/lib/iomgr/wakeup_fd_pipe.c b/src/core/lib/iomgr/wakeup_fd_pipe.c
index 8991d1774197c67a1b92ce18c6e83d2506b9483c..b9754228b1de0267eae6649ab2865852f1dea65a 100644
--- a/src/core/lib/iomgr/wakeup_fd_pipe.c
+++ b/src/core/lib/iomgr/wakeup_fd_pipe.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_WAKEUP_FD
+#ifdef GRPC_POSIX_WAKEUP_FD
 
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 
diff --git a/src/core/lib/iomgr/wakeup_fd_posix.c b/src/core/lib/iomgr/wakeup_fd_posix.c
index c5c4eeb62e85936549dca2cbc10c3933c377c6ed..dc51a08ca20a8e3c3f03c7b762b0a6b3692812f7 100644
--- a/src/core/lib/iomgr/wakeup_fd_posix.c
+++ b/src/core/lib/iomgr/wakeup_fd_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_WAKEUP_FD
+#ifdef GRPC_POSIX_WAKEUP_FD
 
 #include <stddef.h>
 #include "src/core/lib/iomgr/wakeup_fd_pipe.h"
@@ -69,4 +69,4 @@ void grpc_wakeup_fd_destroy(grpc_wakeup_fd *fd_info) {
   wakeup_fd_vtable->destroy(fd_info);
 }
 
-#endif /* GPR_POSIX_WAKEUP_FD */
+#endif /* GRPC_POSIX_WAKEUP_FD */
diff --git a/src/core/lib/iomgr/workqueue.h b/src/core/lib/iomgr/workqueue.h
index 86c7114c3159817b902840e918bf78a9e6fa5d43..3edba4b305ac20d9204daec827e05a7225f11a26 100644
--- a/src/core/lib/iomgr/workqueue.h
+++ b/src/core/lib/iomgr/workqueue.h
@@ -41,7 +41,7 @@
 #include "src/core/lib/iomgr/pollset_set.h"
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 #include "src/core/lib/iomgr/workqueue_posix.h"
 #endif
 
diff --git a/src/core/lib/iomgr/workqueue_posix.c b/src/core/lib/iomgr/workqueue_posix.c
index 2665b9580ffa572fa2d66ade9b397700d930e44c..f28a442718c69edf139fa7a233baf97840c08fd8 100644
--- a/src/core/lib/iomgr/workqueue_posix.c
+++ b/src/core/lib/iomgr/workqueue_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 
 #include "src/core/lib/iomgr/workqueue.h"
 
@@ -148,4 +148,4 @@ void grpc_workqueue_enqueue(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
   gpr_mu_unlock(&workqueue->mu);
 }
 
-#endif /* GPR_POSIX_SOCKET */
+#endif /* GRPC_POSIX_SOCKET */
diff --git a/test/core/end2end/fixtures/h2_full+trace.c b/test/core/end2end/fixtures/h2_full+trace.c
index ad31d21fefea636f660aaef58fbf546a9dc06a36..e25b5e334701d466ad78a548d20ef11ab2fe1aba 100644
--- a/test/core/end2end/fixtures/h2_full+trace.c
+++ b/test/core/end2end/fixtures/h2_full+trace.c
@@ -110,7 +110,7 @@ int main(int argc, char **argv) {
      code paths in trace.c to be taken */
   gpr_setenv("GRPC_TRACE", "doesnt-exist,http,all");
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
   g_fixture_slowdown_factor = isatty(STDOUT_FILENO) ? 10.0 : 1.0;
 #else
   g_fixture_slowdown_factor = 10.0;
diff --git a/test/core/end2end/fixtures/h2_sockpair+trace.c b/test/core/end2end/fixtures/h2_sockpair+trace.c
index 429c2013d356d34660205040451ee67c3362e697..90f815077c0c1d00bb95e3180dea16e8d728ff09 100644
--- a/test/core/end2end/fixtures/h2_sockpair+trace.c
+++ b/test/core/end2end/fixtures/h2_sockpair+trace.c
@@ -147,7 +147,7 @@ int main(int argc, char **argv) {
   /* force tracing on, with a value to force many
      code paths in trace.c to be taken */
   gpr_setenv("GRPC_TRACE", "doesnt-exist,http,all");
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
   g_fixture_slowdown_factor = isatty(STDOUT_FILENO) ? 10.0 : 1.0;
 #else
   g_fixture_slowdown_factor = 10.0;
diff --git a/test/core/iomgr/ev_epoll_linux_test.c b/test/core/iomgr/ev_epoll_linux_test.c
index d7ee6da7c6d2d6904572c38421af0e77ed1fe44d..564b05d7f4c727335dbdd53e1b01d79b53056b01 100644
--- a/test/core/iomgr/ev_epoll_linux_test.c
+++ b/test/core/iomgr/ev_epoll_linux_test.c
@@ -33,7 +33,7 @@
 #include "src/core/lib/iomgr/port.h"
 
 /* This test only relevant on linux systems where epoll() is available */
-#ifdef GPR_LINUX_EPOLL
+#ifdef GRPC_LINUX_EPOLL
 #include "src/core/lib/iomgr/ev_epoll_linux.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 
@@ -239,6 +239,6 @@ int main(int argc, char **argv) {
   grpc_iomgr_shutdown();
   return 0;
 }
-#else /* defined(GPR_LINUX_EPOLL) */
+#else /* defined(GRPC_LINUX_EPOLL) */
 int main(int argc, char **argv) { return 0; }
-#endif /* !defined(GPR_LINUX_EPOLL) */
+#endif /* !defined(GRPC_LINUX_EPOLL) */
diff --git a/test/core/util/port_posix.c b/test/core/util/port_posix.c
index 6e3ab64eddbd5172695ed515aafe65e027ae0f19..60537b49469cfb7c2681100f15d4f32684ada530 100644
--- a/test/core/util/port_posix.c
+++ b/test/core/util/port_posix.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 #include "test/core/util/test_config.h"
-#if defined(GPR_POSIX_SOCKET) && defined(GRPC_TEST_PICK_PORT)
+#if defined(GRPC_POSIX_SOCKET) && defined(GRPC_TEST_PICK_PORT)
 
 #include "test/core/util/port.h"
 
@@ -237,4 +237,4 @@ int grpc_pick_unused_port_or_die(void) {
 
 void grpc_recycle_unused_port(int port) { GPR_ASSERT(free_chosen_port(port)); }
 
-#endif /* GPR_POSIX_SOCKET && GRPC_TEST_PICK_PORT */
+#endif /* GRPC_POSIX_SOCKET && GRPC_TEST_PICK_PORT */
diff --git a/test/core/util/port_windows.c b/test/core/util/port_windows.c
index 4cc0cea0cb884ddbe4570d550ae565181d6b1c5e..db9787dec6d64b75b1e555402d839864cdea32d4 100644
--- a/test/core/util/port_windows.c
+++ b/test/core/util/port_windows.c
@@ -33,7 +33,7 @@
 
 #include "src/core/lib/iomgr/port.h"
 #include "test/core/util/test_config.h"
-#if defined(GPR_WINSOCK_SOCKET) && defined(GRPC_TEST_PICK_PORT)
+#if defined(GRPC_WINSOCK_SOCKET) && defined(GRPC_TEST_PICK_PORT)
 
 #include "test/core/util/port.h"
 
@@ -242,4 +242,4 @@ int grpc_pick_unused_port_or_die(void) {
 
 void grpc_recycle_unused_port(int port) { GPR_ASSERT(free_chosen_port(port)); }
 
-#endif /* GPR_WINSOCK_SOCKET && GRPC_TEST_PICK_PORT */
+#endif /* GRPC_WINSOCK_SOCKET && GRPC_TEST_PICK_PORT */
diff --git a/test/cpp/end2end/async_end2end_test.cc b/test/cpp/end2end/async_end2end_test.cc
index 662ccbd1c2cceeaabd55b559e50738315e3222b2..b5c95bca86d9d8e77234b10f783a7536c32ea151 100644
--- a/test/cpp/end2end/async_end2end_test.cc
+++ b/test/cpp/end2end/async_end2end_test.cc
@@ -55,7 +55,7 @@
 #include "test/cpp/util/string_ref_helper.h"
 #include "test/cpp/util/test_credentials_provider.h"
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 #include "src/core/lib/iomgr/ev_posix.h"
 #endif
 
@@ -74,7 +74,7 @@ namespace {
 void* tag(int i) { return (void*)(intptr_t)i; }
 int detag(void* p) { return static_cast<int>(reinterpret_cast<intptr_t>(p)); }
 
-#ifdef GPR_POSIX_SOCKET
+#ifdef GRPC_POSIX_SOCKET
 static int maybe_assert_non_blocking_poll(struct pollfd* pfds, nfds_t nfds,
                                           int timeout) {
   if (gpr_tls_get(&g_is_async_end2end_test)) {