diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index 7554198..cd09e3d 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -118,6 +118,9 @@
 extern int fchdir(int);
 extern int rmdir(const char *);
 extern int pipe(int *);
+#ifdef _GNU_SOURCE  /* GLibc compatibility */
+extern int pipe2(int *, int);
+#endif
 extern int chroot(const char *);
 extern int symlink(const char *, const char *);
 extern int readlink(const char *, char *, size_t);