diff --git a/graphics/ruby-gdal/Makefile b/graphics/ruby-gdal/Makefile
index 5c32876a3c44..35610a501d74 100644
--- a/graphics/ruby-gdal/Makefile
+++ b/graphics/ruby-gdal/Makefile
@@ -1,42 +1,42 @@
 # Created by: Sunpoet Po-Chuan Hsieh <sunpoet@FreeBSD.org>
 # $FreeBSD$
 
 PORTNAME=	gdal
 PORTVERSION=	2.0.1
 CATEGORIES=	graphics ruby
 MASTER_SITES=	http://download.osgeo.org/gdal/${PORTVERSION}/ \
 		ftp://ftp.remotesensing.org/pub/gdal/${PORTVERSION}/ \
 		LOCAL/sunpoet
 PKGNAMEPREFIX=	${RUBY_PKGNAMEPREFIX}
 
 MAINTAINER=	sunpoet@FreeBSD.org
 COMMENT=	Ruby binding for GDAL
 
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/../../LICENSE.TXT
 
 BUILD_DEPENDS=	swig3.0:${PORTSDIR}/devel/swig30
 LIB_DEPENDS=	libgdal.so:${PORTSDIR}/graphics/gdal
 
 IGNORE=		disabled by upstream (https://trac.osgeo.org/gdal/changeset/28756)
 
 MAKE_ARGS=	USER_DEFS=-fPIC
 MAKEFILE=	GNUmakefile
 USE_RUBY=	yes
 USES=		gmake tar:xz
 
-WRKSRC=		${WRKDIR}/${DISTNAME}/swig/ruby
+WRKSRC_SUBDIR=	swig/ruby
 
 post-patch:
 	@${REINPLACE_CMD} -e '/^SWIG = swig/ s|$$|3.0|' ${WRKSRC}/../SWIGmake.base
 	@${REINPLACE_CMD} -e 's|Config::CONFIG|Rb&|g' ${WRKSRC}/RubyMakefile.mk
 
 # include/cpl_config.h will only exist after graphics/gdal (build dependency) installed
 pre-configure:
 	@${SED} -e '/^GDAL_ROOT/d' ${DATADIR}/GDALmake.opt > ${WRKSRC}/../../GDALmake.opt
 	@${CP} ${LOCALBASE}/include/cpl_config.h ${WRKSRC}/../../port/
 
 post-install:
 	${STRIP_CMD} ${STAGEDIR}${RUBY_SITELIBDIR}/${RUBY_ARCH}/gdal/*.so
 
 .include <bsd.port.mk>