diff --git a/net/lualdap/Makefile b/net/lualdap/Makefile
index 663a92126188..e09f0deae11e 100644
--- a/net/lualdap/Makefile
+++ b/net/lualdap/Makefile
@@ -1,36 +1,37 @@
 PORTNAME=	lualdap
 PORTVERSION=	1.3.0
 DISTVERSIONPREFIX=	v
 PORTREVISION=	0
 CATEGORIES=	net
 PKGNAMEPREFIX=	${LUA_PKGNAMEPREFIX}
 
 MAINTAINER=	ports@FreeBSD.org
 COMMENT=	LDAP support for the Lua language
 WWW=		https://github.com/lualdap/lualdap
 
 LICENSE=	MIT
 
 USES=		gmake lua:module
 USE_OPENLDAP=	yes
 USE_GITHUB=	yes
+USE_CSTD=	c99
 
 MAKE_ARGS+=	CPPFLAGS="-I${LOCALBASE}/include -I${LUA_INCDIR}" \
 		LDFLAGS="-L${LOCALBASE}/lib" \
 		CC="${CC}"
 
 ALL_TARGET=
 
 OPTIONS_DEFINE=	DOCS
 
 DOCSDIR=	${LUA_DOCSDIR}
 
 do-install:
 	@${MKDIR} ${STAGEDIR}${LUA_MODLIBDIR}
 	${INSTALL_PROGRAM} ${WRKSRC}/src/lualdap.so ${STAGEDIR}${LUA_MODLIBDIR}/${PORTNAME}.so
 
 do-install-DOCS-on:
 	@${MKDIR} ${STAGEDIR}${DOCSDIR}
 	${INSTALL_DATA} ${WRKSRC}/docs/*.md ${STAGEDIR}${DOCSDIR}
 
 .include <bsd.port.mk>