diff --git a/sys/unix/Makefile.utl b/sys/unix/Makefile.utl
index 3fe09817a..be6299298 100644
--- a/sys/unix/Makefile.utl
+++ b/sys/unix/Makefile.utl
@@ -97,7 +97,7 @@ NHSROOT=..
 #CFLAGS = -O -I../include
 #LFLAGS =
 
-CFLAGS += -I../lib/lua-5.3.5/src
+CFLAGS += -I../lib/lua-$(LUA_VERSION)/src
 LFLAGS += -lm
 
 # we specify C preprocessor flags via CFLAGS; files built with default rules