diff --git a/src/threads.h b/src/threads.h
index c0c1522a0fb883d81fc8ed52c898d6a8e3516b22..816c87d88b0b767361f85134d7ad15ae19843ddd 100644
--- a/src/threads.h
+++ b/src/threads.h
@@ -1,5 +1,5 @@
 /*
- * $Id: threads.h,v 1.103 2000/08/11 10:46:22 grubba Exp $
+ * $Id: threads.h,v 1.104 2000/10/03 19:13:24 grubba Exp $
  */
 #ifndef THREADS_H
 #define THREADS_H
@@ -117,7 +117,12 @@ extern pthread_attr_t small_pattr;
 #define th_create_small(ID,fun,arg) pthread_create(ID,&small_pattr,fun,arg)
 #define th_exit(foo) pthread_exit(foo)
 #define th_self() pthread_self()
+#ifdef HAVE_PTHREAD_KILL
 #define th_kill(ID,sig) pthread_kill((ID),(sig))
+#else /* !HAVE_PTHREAD_KILL */
+/* MacOS X (aka Darwin) doesn't have pthread_kill. */
+#define th_kill(ID,sig)
+#endif /* HAVE_PTHREAD_KILL */
 #define th_join(ID,res) pthread_join((ID),(res))
 #ifdef HAVE_PTHREAD_COND_INIT
 #define COND_T pthread_cond_t