diff --git a/lib/Makefile b/lib/Makefile
index 52abe21..879da18 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -9,8 +9,8 @@ include ../Makefile.rule
 
 
 
-DEP     = libnode.h ../include/node.h Makefile
-INCLUDE = -I . -I ../include
+DEP     += libnode.h ../include/node.h Makefile
+INCLUDE += -I . -I ../include
 
 ifdef _LIBVER_SUPPORT
 	DEP     += ../../libver/ver.h