Index: thread_pthread.c
===================================================================
--- thread_pthread.c	(revision 36995)
+++ thread_pthread.c	(working copy)
@@ -264,6 +264,7 @@ native_cond_initialize(rb_thread_cond_t *cond, int
 #  endif
 
     r = pthread_cond_init(&cond->cond, &attr);
+    pthread_condattr_destroy(&attr);
 # else
     r = pthread_cond_init(&cond->cond, NULL);
 # endif