diff --git a/share/mk/bsd.own.mk b/share/mk/bsd.own.mk
index cf3bee6b2f0..9f33424cae2 100644
--- a/share/mk/bsd.own.mk
+++ b/share/mk/bsd.own.mk
@@ -133,12 +133,23 @@ CTFCONVERT_CMD=	@:
 .endif 
 
 .if ${MK_INSTALL_AS_USER} != "no"
+.if !defined(_uid)
 _uid!=	id -u
+.export _uid
+.endif
 .if ${_uid} != 0
 .if !defined(USER)
-USER!=	id -un
+# Avoid exporting USER
+.if !defined(_USER)
+_USER!=	id -un
+.export _USER
 .endif
+USER=	${_USER}
+.endif
+.if !defined(_gid)
 _gid!=	id -g
+.export _gid
+.endif
 .for x in BIN CONF DOC DTB INFO KMOD LIB MAN NLS SHARE
 $xOWN=	${USER}
 $xGRP=	${_gid}