diff --git a/base/allocator/allocator_shim_internals.h b/base/allocator/allocator_shim_internal
s.h
index 0196f89..bb42b5d 100644
--- a/base/allocator/allocator_shim_internals.h
+++ b/base/allocator/allocator_shim_internals.h
@@ -7,7 +7,9 @@

 #if defined(__GNUC__)

+#if defined(__GLIBC__)
 #include <sys/cdefs.h>  // for __THROW
+#endif

 #ifndef __THROW  // Not a glibc system
 #ifdef _NOEXCEPT  // LLVM libc++ uses noexcept instead
diff --git a/third_party/libsync/src/include/sync/sync.h b/third_party/libsync/src/include/sync/sync.h
index 50ed0ac..7552a49 100644
--- a/third_party/libsync/src/include/sync/sync.h
+++ b/third_party/libsync/src/include/sync/sync.h
@@ -19,12 +19,13 @@
 #ifndef __SYS_CORE_SYNC_H
 #define __SYS_CORE_SYNC_H
 
-#include <sys/cdefs.h>
 #include <stdint.h>
 
 #include <linux/types.h>
 
-__BEGIN_DECLS
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
 
 struct sync_legacy_merge_data {
  int32_t fd2;
@@ -158,6 +159,8 @@ struct sync_pt_info *sync_pt_info(struct sync_fence_info_data *info,
                                   struct sync_pt_info *itr);
 void sync_fence_info_free(struct sync_fence_info_data *info);
 
-__END_DECLS
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
 
 #endif /* __SYS_CORE_SYNC_H */