diff --git a/biology/mothur/Makefile b/biology/mothur/Makefile
index 4a8a6aa6cd57..8c2bde5c481e 100644
--- a/biology/mothur/Makefile
+++ b/biology/mothur/Makefile
@@ -1,29 +1,30 @@
 PORTNAME=	mothur
 DISTVERSIONPREFIX=	v
 DISTVERSION=	1.48.0
 CATEGORIES=	biology
 
 MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Software for bioinformatics of the microbial ecology community
 WWW=		https://www.mothur.org/
 
 LICENSE=	GPLv3
 LICENSE_FILE=	${WRKSRC}/LICENSE.md
 
 BUILD_DEPENDS=	bash:shells/bash
 
 USES=		compiler:c++11-lang gmake localbase readline
 USE_GITHUB=	yes
+USE_CXXSTD=	c++11 # not all C++ files are compiled with -std=c++11 which causes failure in addtargets2.cpp due to a collision of the 'byte' symbol with std::byte
 
 MAKE_ARGS=	INSTALL_DIR=${STAGEDIR}${PREFIX}/bin
 
 ALL_TARGET=	${PORTNAME}
 
 BINARY_ALIAS=	g++=${CXX}
 
 PLIST_FILES=	bin/${PORTNAME}
 
 post-install:
 	@${STRIP_CMD} ${STAGEDIR}${PREFIX}/bin/${PORTNAME}
 
 .include <bsd.port.mk>