diff --git a/lang/siod/Makefile b/lang/siod/Makefile
index 8de9413cb4d3..98c32232ba31 100644
--- a/lang/siod/Makefile
+++ b/lang/siod/Makefile
@@ -28,8 +28,7 @@ NO_WRKSUBDIR=	yes
 EXTRACT_AFTER_ARGS=--exclude md5\* --exclude regex.h --exclude reg????*.c
 MAKE_ARGS=	VPATH=${WRKSRC} MODULES=${MODULES:Q}
 MAKEFILE=	${FILESDIR}/BSDmakefile
-MAKE_ENV=	MKDIR=${MKDIR:Q} STAGEDIR=${STAGEDIR:Q}
-MAKE_ENV+=	MAN1PREFIX=${PREFIX}/share PREFIX=${PREFIX:Q}
+MAKE_ENV=	MKDIR=${MKDIR:Q} PREFIX=${PREFIX:Q} STAGEDIR=${STAGEDIR:Q}
 MAKE_ENV+=	INSTALL_MAN=${INSTALL_MAN:Q} INSTALL_SCRIPT=${INSTALL_SCRIPT:Q}
 MAKE_ENV+=	INSTALL_DATA=${INSTALL_DATA:Q}