diff --git a/libc/include/fcntl.h b/libc/include/fcntl.h
index db56ce3..f57c320 100644
--- a/libc/include/fcntl.h
+++ b/libc/include/fcntl.h
@@ -46,6 +46,7 @@
 #endif
 
 #define O_ASYNC FASYNC
+#define O_RSYNC O_SYNC
 
 #define SPLICE_F_MOVE 1
 #define SPLICE_F_NONBLOCK 2
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index 52f71dd..80a6578 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -59,8 +59,15 @@
 
 extern char* mkdtemp(char*);
 extern char* mktemp(char*) __warnattr("mktemp possibly used unsafely; consider using mkstemp");
-extern int mkstemp(char*);
+
+extern int mkostemp64(char*, int);
+extern int mkostemp(char*, int);
+extern int mkostemps64(char*, int, int);
+extern int mkostemps(char*, int, int);
 extern int mkstemp64(char*);
+extern int mkstemp(char*);
+extern int mkstemps64(char*, int);
+extern int mkstemps(char*, int);
 
 extern long strtol(const char *, char **, int);
 extern long long strtoll(const char *, char **, int);
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index 20bc1a3..475ee1af 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -169,9 +169,7 @@
 
 extern int dup(int);
 extern int dup2(int, int);
-#if defined(__USE_GNU)
 extern int dup3(int, int, int);
-#endif
 extern int fcntl(int, int, ...);
 extern int ioctl(int, int, ...);
 extern int flock(int, int);