Index: Makefile
===================================================================
--- Makefile	(revision 512126)
+++ Makefile	(working copy)
@@ -98,8 +98,13 @@
 
 .include <bsd.port.pre.mk>
 
+.ifdef MAKE_JOBS_NUMBER
 MAKE_ENV+=	MAKE="${MAKE} -j${MAKE_JOBS_NUMBER}"
+.else
+MAKE_ENV+=	MAKE="${MAKE}"
+.endif
 
+
 .ifdef MAINTAINER_MODE
 test-fbsd-patches:	patch
 	${RM} -r ${WRKSRC}/build/pkgs/*/src; \