diff --git a/src/share/mk/bsd.own.mk b/src/share/mk/bsd.own.mk
index 9bdc7c7..518440e 100644
--- a/src/share/mk/bsd.own.mk
+++ b/src/share/mk/bsd.own.mk
@@ -1155,7 +1155,7 @@ INSTPRIV?=	${INSTPRIV.unpriv} -N ${NETBSDSRCDIR}/etc
 STRIPFLAG?=	
 
 .if ${NEED_OWN_INSTALL_TARGET} != "no"
-INSTALL_DIR?=		${INSTALL} ${INSTPRIV} -d
+INSTALL_DIR =		${INSTALL} ${INSTPRIV} -d
 INSTALL_FILE?=		${INSTALL} ${INSTPRIV} ${COPY} ${PRESERVE} ${RENAME}
 INSTALL_LINK?=		${INSTALL} ${INSTPRIV} ${HRDLINK} ${RENAME}
 INSTALL_SYMLINK?=	${INSTALL} ${INSTPRIV} ${SYMLINK} ${RENAME}