diff --git a/libc/include/semaphore.h b/libc/include/semaphore.h
index 218f22a..7e3dc1c 100644
--- a/libc/include/semaphore.h
+++ b/libc/include/semaphore.h
@@ -44,19 +44,19 @@
 
 #define SEM_FAILED __BIONIC_CAST(reinterpret_cast, sem_t*, 0)
 
-int sem_destroy(sem_t*);
-int sem_getvalue(sem_t*, int*);
-int sem_init(sem_t*, int, unsigned int);
-int sem_post(sem_t*);
-int sem_timedwait(sem_t*, const struct timespec*);
-int sem_trywait(sem_t*);
-int sem_wait(sem_t*);
+int sem_destroy(sem_t* __sem);
+int sem_getvalue(sem_t* __sem, int* __value);
+int sem_init(sem_t* __sem, int __shared, unsigned int __value);
+int sem_post(sem_t* __sem);
+int sem_timedwait(sem_t* __sem, const struct timespec* __ts);
+int sem_trywait(sem_t* __sem);
+int sem_wait(sem_t* __sem);
 
 /* These aren't actually implemented. */
-sem_t* sem_open(const char*, int, ...);
-int sem_close(sem_t*);
-int sem_unlink(const char*);
+sem_t* sem_open(const char* __name, int _flags, ...);
+int sem_close(sem_t* __sem);
+int sem_unlink(const char* __name);
 
 __END_DECLS
 
-#endif /* _SEMAPHORE_H */
+#endif