--- src/threads/thread.cpp.orig	2012-09-03 12:10:00.000000000 -0400
+++ src/threads/thread.cpp	2012-10-04 16:37:45.000000000 -0400
@@ -37,6 +37,8 @@
 
 #if defined(__LINUX__)
 # define GC_LINUX_THREADS
+#elif defined(__FREEBSD__)
+# define GC_FREEBSD_THREADS
 #elif defined(__IRIX__)
 # define GC_IRIX_THREADS
 #elif defined(__DARWIN__)