--- a/pagespeed/kernel/thread/pthread_rw_lock.cc
+++ b/pagespeed/kernel/thread/pthread_rw_lock.cc
@@ -31,7 +31,7 @@
   //
   // Other OS's (FreeBSD, Darwin, OpenSolaris) documentation suggests
   // that they prefer writers by default.
-#ifdef linux
+#if defined(linux) && defined(__GLIBC__)
   pthread_rwlockattr_setkind_np(&attr_,
                                 PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
 #endif