diff --git a/make-linux.mk b/make-linux.mk
index 2ef9b9850..5e0a20726 100644
--- a/make-linux.mk
+++ b/make-linux.mk
@@ -29,7 +29,7 @@ endif
 UNAME_M=$(shell uname -m)
 
 INCLUDES=
-DEFS=
+DEFS=-DZT_ENABLE_CLUSTER
 LDLIBS?=
 
 include objects.mk