diff --git a/include/nccl-headers/neuron/error.h b/include/nccl-headers/neuron/error.h
index 25062d0ff..de93857b1 100644
--- a/include/nccl-headers/neuron/error.h
+++ b/include/nccl-headers/neuron/error.h
@@ -6,7 +6,7 @@
 #ifndef NCCL_HEADERS_NEURON_ERROR_H_
 #define NCCL_HEADERS_NEURON_ERROR_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -21,7 +21,7 @@ typedef enum {
 	ncclRemoteError = 6
 } ncclResult_t;
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 }
 #endif
 
diff --git a/include/nccl-headers/neuron/net.h b/include/nccl-headers/neuron/net.h
index 8f6a841e8..00905ff9d 100644
--- a/include/nccl-headers/neuron/net.h
+++ b/include/nccl-headers/neuron/net.h
@@ -6,7 +6,7 @@
 #ifndef NCCL_HEADERS_NEURON_NET_H_
 #define NCCL_HEADERS_NEURON_NET_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -100,7 +100,7 @@ typedef struct {
 	ncclResult_t (*closeListen)(void* listenComm);
 } ncclNet_v4_t;
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi.h b/include/nccl_ofi.h
index 680ee4844..e502f6cc9 100644
--- a/include/nccl_ofi.h
+++ b/include/nccl_ofi.h
@@ -5,7 +5,8 @@
 #ifndef NCCL_OFI_H_
 #define NCCL_OFI_H_
 
-#ifdef _cplusplus
+
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -23,7 +24,6 @@ extern "C" {
 #include "nccl_ofi_idpool.h"
 #include "nccl_ofi_mr.h"
 
-
 /*
  * NCCL_NET_HANDLE_MAXSIZE is a limited resource (and defined in NCCL).
  * An endpoint address buffer of 56 bytes *should* be large enough to hold
@@ -590,7 +590,7 @@ int nccl_net_ofi_dealloc_mr_buffer(void *ptr, size_t size);
 int nccl_net_ofi_query_provider_capabilities(const struct fi_info *selected_provider,
 					     unsigned int num_providers);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_api.h b/include/nccl_ofi_api.h
index a7bd41372..a023e1788 100644
--- a/include/nccl_ofi_api.h
+++ b/include/nccl_ofi_api.h
@@ -6,13 +6,14 @@
 #ifndef NET_OFI_API_H_
 #define NET_OFI_API_H_
 
-#include "nccl-headers/net.h"
-#include "nccl-headers/error.h"
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
+#include "nccl-headers/net.h"
+#include "nccl-headers/error.h"
+
 struct nccl_ofi_properties;
 
 ncclResult_t nccl_net_ofi_init(ncclDebugLogger_t logFunction);
@@ -42,7 +43,7 @@ ncclResult_t nccl_net_ofi_closeSend(void *sendComm);
 ncclResult_t nccl_net_ofi_closeRecv(void *recvComm);
 ncclResult_t nccl_net_ofi_closeListen(void *listenComm);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 }
 #endif // End extern "C"
 
diff --git a/include/nccl_ofi_cuda.h b/include/nccl_ofi_cuda.h
index 080ebc0d9..322a5db94 100644
--- a/include/nccl_ofi_cuda.h
+++ b/include/nccl_ofi_cuda.h
@@ -6,7 +6,8 @@
 #ifndef NCCL_OFI_CUDA_H_
 #define NCCL_OFI_CUDA_H_
 
-#ifdef _cplusplus
+
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -41,7 +42,7 @@ extern CUresult (*nccl_net_ofi_cuFlushGPUDirectRDMAWrites)(CUflushGPUDirectRDMAW
 extern void *nccl_net_ofi_cuFlushGPUDirectRDMAWrites;
 #endif
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_deque.h b/include/nccl_ofi_deque.h
index b29245947..3a71ce719 100644
--- a/include/nccl_ofi_deque.h
+++ b/include/nccl_ofi_deque.h
@@ -5,7 +5,8 @@
 #ifndef NCCL_OFI_DEQUE_H
 #define NCCL_OFI_DEQUE_H
 
-#ifdef _cplusplus
+
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -162,7 +163,7 @@ static inline int nccl_ofi_deque_remove_front(nccl_ofi_deque_t *deque, nccl_ofi_
 	return 0;
 }
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_ep_addr_list.h b/include/nccl_ofi_ep_addr_list.h
index ae41d284e..9eea01396 100644
--- a/include/nccl_ofi_ep_addr_list.h
+++ b/include/nccl_ofi_ep_addr_list.h
@@ -5,6 +5,10 @@
 #ifndef NCCL_OFI_EP_ADDR_LIST_H
 #define NCCL_OFI_EP_ADDR_LIST_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct nccl_ofi_ep_addr_list;
 typedef struct nccl_ofi_ep_addr_list nccl_ofi_ep_addr_list_t;
 
@@ -76,4 +80,8 @@ int nccl_ofi_ep_addr_list_delete(nccl_ofi_ep_addr_list_t *ep_list, nccl_net_ofi_
  */
 void nccl_ofi_ep_addr_list_fini(nccl_ofi_ep_addr_list_t *ep_list);
 
+#ifdef __cplusplus
+} // End extern "C"
+#endif
+
 #endif
diff --git a/include/nccl_ofi_freelist.h b/include/nccl_ofi_freelist.h
index 17d9e351e..089128019 100644
--- a/include/nccl_ofi_freelist.h
+++ b/include/nccl_ofi_freelist.h
@@ -5,7 +5,8 @@
 #ifndef NCCL_OFI_FREELIST_H
 #define NCCL_OFI_FREELIST_H
 
-#ifdef _cplusplus
+
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -313,7 +314,7 @@ static inline void nccl_ofi_freelist_entry_free(nccl_ofi_freelist_t *freelist, v
 	nccl_net_ofi_mutex_unlock(&freelist->lock);
 }
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_idpool.h b/include/nccl_ofi_idpool.h
index 7e2745abf..97c7bfdf4 100644
--- a/include/nccl_ofi_idpool.h
+++ b/include/nccl_ofi_idpool.h
@@ -5,12 +5,12 @@
 #ifndef NCCL_OFI_IDPOOL_H_
 #define NCCL_OFI_IDPOOL_H_
 
-#ifdef _cplusplus
+
+#ifdef __cplusplus
 extern "C" {
 #endif
 
 #include <pthread.h>
-
 #include <stdint.h>
 
 /*
@@ -87,7 +87,7 @@ int nccl_ofi_idpool_free_id(nccl_ofi_idpool_t *idpool, int id);
  */
 int nccl_ofi_idpool_fini(nccl_ofi_idpool_t *idpool);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_log.h b/include/nccl_ofi_log.h
index df58688c2..52a02ec8c 100644
--- a/include/nccl_ofi_log.h
+++ b/include/nccl_ofi_log.h
@@ -6,7 +6,7 @@
 #ifndef NCCL_OFI_LOG_H_
 #define NCCL_OFI_LOG_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -33,7 +33,7 @@ extern ncclDebugLogger_t ofi_log_function;
 #define NCCL_OFI_TRACE(flags, fmt, ...)
 #endif
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_math.h b/include/nccl_ofi_math.h
index 9b6134e8e..75b2c4938 100644
--- a/include/nccl_ofi_math.h
+++ b/include/nccl_ofi_math.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_MATH_H_
 #define NCCL_OFI_MATH_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -65,7 +65,7 @@ extern "C" {
  */
 #define NCCL_OFI_ROUND_UP(x, y) NCCL_OFI_ROUND_DOWN((x) + ((y) - 1), (y))
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_memcheck.h b/include/nccl_ofi_memcheck.h
index fe8d59e5b..20eb8bf46 100644
--- a/include/nccl_ofi_memcheck.h
+++ b/include/nccl_ofi_memcheck.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_MEMCHECK_H
 #define NCCL_OFI_MEMCHECK_H
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -169,7 +169,7 @@ static inline void nccl_net_ofi_mem_mempool_alloc(void *handle, void *data, size
  */
 static inline void nccl_net_ofi_mem_mempool_free(void *handle, void *data, size_t size);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_memcheck_asan.h b/include/nccl_ofi_memcheck_asan.h
index 32476b199..baab829aa 100644
--- a/include/nccl_ofi_memcheck_asan.h
+++ b/include/nccl_ofi_memcheck_asan.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_MEMCHECK_ASAN_H
 #define NCCL_OFI_MEMCHECK_ASAN_H
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -56,7 +56,7 @@ static inline void nccl_net_ofi_mem_mempool_free(void *handle, void *data, size_
 	nccl_net_ofi_mem_noaccess(data, size);
 }
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_memcheck_nop.h b/include/nccl_ofi_memcheck_nop.h
index 9c15a8ff1..17e4d1e50 100644
--- a/include/nccl_ofi_memcheck_nop.h
+++ b/include/nccl_ofi_memcheck_nop.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_MEMCHECK_NOP_H
 #define NCCL_OFI_MEMCHECK_NOP_H
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -44,7 +44,7 @@ static inline void nccl_net_ofi_mem_mempool_free(void *handle, void *data, size_
 {
 }
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_memcheck_valgrind.h b/include/nccl_ofi_memcheck_valgrind.h
index dbc111167..dfd64a62c 100644
--- a/include/nccl_ofi_memcheck_valgrind.h
+++ b/include/nccl_ofi_memcheck_valgrind.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_MEMCHECK_VALGRIND_H
 #define NCCL_OFI_MEMCHECK_VALGRIND_H
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -48,7 +48,7 @@ static inline void nccl_net_ofi_mem_mempool_free(void *handle, void *data, size_
 	VALGRIND_MEMPOOL_FREE(handle, data);
 }
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_mr.h b/include/nccl_ofi_mr.h
index 3b0ae5b35..e782e5cfa 100644
--- a/include/nccl_ofi_mr.h
+++ b/include/nccl_ofi_mr.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_MR_H_
 #define NCCL_OFI_MR_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -80,7 +80,7 @@ int nccl_ofi_mr_cache_insert_entry(nccl_ofi_mr_cache_t *cache,
  */
 int nccl_ofi_mr_cache_del_entry(nccl_ofi_mr_cache_t *cache, void *handle);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 }  // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_msgbuff.h b/include/nccl_ofi_msgbuff.h
index cf51fcdf4..51b6a66e7 100644
--- a/include/nccl_ofi_msgbuff.h
+++ b/include/nccl_ofi_msgbuff.h
@@ -5,12 +5,11 @@
 #ifndef NCCL_OFI_MSGBUFF_H_
 #define NCCL_OFI_MSGBUFF_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
 #include <pthread.h>
-
 #include <stdbool.h>
 #include <stdint.h>
 
@@ -183,7 +182,7 @@ nccl_ofi_msgbuff_result_t nccl_ofi_msgbuff_retrieve(nccl_ofi_msgbuff_t *msgbuff,
 nccl_ofi_msgbuff_result_t nccl_ofi_msgbuff_complete(nccl_ofi_msgbuff_t *msgbuff,
 		uint16_t msg_index, nccl_ofi_msgbuff_status_t *msg_idx_status);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_ofiutils.h b/include/nccl_ofi_ofiutils.h
index 37a09b854..ce6d241bd 100644
--- a/include/nccl_ofi_ofiutils.h
+++ b/include/nccl_ofi_ofiutils.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_OFIUTILS_H
 #define NCCL_OFI_OFIUTILS_H
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -43,7 +43,7 @@ void nccl_ofi_ofiutils_free_info_list(struct fi_info *info_list);
 
 int nccl_ofi_mr_keys_need_own_key(struct fi_info* provider, bool *provide_own_mr_key);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_param.h b/include/nccl_ofi_param.h
index f4cf188d6..7ae619c35 100644
--- a/include/nccl_ofi_param.h
+++ b/include/nccl_ofi_param.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_PARAM_H_
 #define NCCL_OFI_PARAM_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -240,7 +240,7 @@ OFI_NCCL_PARAM_INT(errorcheck_mutex, "ERRORCHECK_MUTEX",
  */
 OFI_NCCL_PARAM_INT(endpoint_per_communicator, "ENDPOINT_PER_COMM", 0);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_platform.h b/include/nccl_ofi_platform.h
index d79b1006c..257fa22f6 100644
--- a/include/nccl_ofi_platform.h
+++ b/include/nccl_ofi_platform.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_PLATFORM_H_
 #define NCCL_OFI_PLATFORM_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -35,4 +35,8 @@ int platform_config_endpoint(struct fi_info *info, struct fid_ep *ep) __attribut
  */
 void platform_sort_rails(struct fi_info **info_list, int num_rails) __attribute__((weak));
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif // End NCCL_OFI_PLATFORM_H_
diff --git a/include/nccl_ofi_pthread.h b/include/nccl_ofi_pthread.h
index 1222943d6..36137ee9d 100644
--- a/include/nccl_ofi_pthread.h
+++ b/include/nccl_ofi_pthread.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_PTHREAD_H
 #define NCCL_OFI_PTHREAD_H
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -104,7 +104,7 @@ nccl_net_ofi_mutex_unlock_impl(pthread_mutex_t *mutex, const char *file, size_t
 #define nccl_net_ofi_mutex_unlock(mutex) nccl_net_ofi_mutex_unlock_impl(mutex, __FILE__, __LINE__);
 
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_rdma.h b/include/nccl_ofi_rdma.h
index 224a1b8d5..6c906446f 100644
--- a/include/nccl_ofi_rdma.h
+++ b/include/nccl_ofi_rdma.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_RDMA_H_
 #define NCCL_OFI_RDMA_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -761,7 +761,7 @@ typedef struct nccl_net_ofi_rdma_device {
 int nccl_net_ofi_rdma_init(const char *provider_filter,
 			   nccl_net_ofi_plugin_t **plugin_p);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_scheduler.h b/include/nccl_ofi_scheduler.h
index 4d4c5482f..e7e7a828c 100644
--- a/include/nccl_ofi_scheduler.h
+++ b/include/nccl_ofi_scheduler.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_SCHEDULER_H_
 #define NCCL_OFI_SCHEDULER_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -134,7 +134,7 @@ void nccl_net_ofi_set_multiplexing_schedule(size_t size,
 					    size_t align,
 					    nccl_net_ofi_schedule_t *schedule);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_sendrecv.h b/include/nccl_ofi_sendrecv.h
index 433b69704..7309b75f6 100644
--- a/include/nccl_ofi_sendrecv.h
+++ b/include/nccl_ofi_sendrecv.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_OFI_SENDRECV_H_
 #define NCCL_OFI_SENDRECV_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -226,7 +226,7 @@ typedef struct nccl_net_ofi_sendrecv_req {
 int nccl_net_ofi_sendrecv_init(const char *provider_filter,
 			       nccl_net_ofi_plugin_t **plugin_p);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 } // End extern "C"
 #endif
 
diff --git a/include/nccl_ofi_topo.h b/include/nccl_ofi_topo.h
index 8d51e354c..287faf823 100644
--- a/include/nccl_ofi_topo.h
+++ b/include/nccl_ofi_topo.h
@@ -5,7 +5,7 @@
 #ifndef NCCL_NET_OFI_TOPO_H_
 #define NCCL_NET_OFI_TOPO_H_
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -315,7 +315,7 @@ struct fi_info *nccl_ofi_topo_next_info_list(nccl_ofi_topo_data_iterator_t *iter
  */
 int nccl_ofi_topo_write_nccl_topology(nccl_ofi_topo_t *topo, FILE *file);
 
-#ifdef _cplusplus
+#ifdef __cplusplus
 }
 #endif