diff --git a/Makefile.libcompat b/Makefile.libcompat
--- a/Makefile.libcompat
+++ b/Makefile.libcompat
@@ -12,7 +12,7 @@
 LIBCOMPATWMAKEENV+= \
 		INSTALL="${INSTALL_CMD} -U" \
 		PATH=${TMPPATH} \
-		SYSROOT=${LIBCOMPATTMP} \
+		SYSROOT=${WORLDTMP} \
 		LIBDIR=/usr/lib${libcompat} \
 		SHLIBDIR=/usr/lib${libcompat} \
 		DTRACE="${LIB$COMPATDTRACE:U${DTRACE}}"
@@ -23,7 +23,7 @@
 LIBCOMPATWMAKEFLAGS+= CC="${XCC} ${LIBCOMPATCFLAGS}" \
 		CXX="${XCXX} ${LIBCOMPATCXXFLAGS} ${LIBCOMPATCFLAGS}" \
 		CPP="${XCPP} ${LIBCOMPATCFLAGS}" \
-		DESTDIR=${LIBCOMPATTMP} \
+		DESTDIR=${WORLDTMP} \
 		-DNO_CPU_CFLAGS \
 		MK_BOOT=no \
 		MK_CTF=no \
@@ -62,38 +62,12 @@
 	@echo "--------------------------------------------------------------"
 	@echo ">>> stage 4.3: building lib${libcompat} shim libraries"
 	@echo "--------------------------------------------------------------"
-.if ${MK_CLEAN} == "yes"
-	rm -rf ${LIBCOMPATTMP}
-.else
-	${_+_}@if [ -e "${LIBCOMPATTMP}" ]; then \
-		echo ">>> Deleting stale files in build${libcompat} tree..."; \
-		cd ${.CURDIR}; ${WMAKE} -DBATCH_DELETE_OLD_FILES \
-		    DESTDIR=${LIBCOMPATTMP} \
-		    delete-old delete-old-libs >/dev/null; \
-	fi
-.endif	# MK_CLEAN == "yes"
-
-	mkdir -p ${LIBCOMPATTMP}/usr/include
-	${WORLDTMP_MTREE} -f ${.CURDIR}/etc/mtree/BSD.usr.dist \
-	    -p ${LIBCOMPATTMP}/usr >/dev/null
-	${WORLDTMP_MTREE} -f ${.CURDIR}/etc/mtree/BSD.include.dist \
-	    -p ${LIBCOMPATTMP}/usr/include >/dev/null
 	${WORLDTMP_MTREE} -f ${.CURDIR}/etc/mtree/BSD.lib${libcompat}.dist \
-	    -p ${LIBCOMPATTMP}/usr >/dev/null
+	    -p ${WORLDTMP}/usr >/dev/null
 .if ${MK_DEBUG_FILES} != "no"
-	${WORLDTMP_MTREE} -f ${.CURDIR}/etc/mtree/BSD.debug.dist \
-	    -p ${LIBCOMPATTMP}/usr/lib >/dev/null
 	${WORLDTMP_MTREE} -f ${.CURDIR}/etc/mtree/BSD.lib${libcompat}.dist \
-	    -p ${LIBCOMPATTMP}/usr/lib/debug/usr >/dev/null
+	    -p ${WORLDTMP}/usr/lib/debug/usr >/dev/null
 .endif
-	mkdir -p ${WORLDTMP}
-	ln -sf ${.CURDIR}/sys ${WORLDTMP}
-.for _t in ${_obj} includes
-.for _dir in ${_LC_INCDIRS}
-	${_+_}cd ${.CURDIR}/${_dir}; ${LIBCOMPATWMAKE} MK_INCLUDES=yes \
-	    DIRPRFX=${_dir}/ ${_t}
-.endfor
-.endfor
 .for _dir in lib/ncurses/tinfo ${_libmagic} ${_jevents}
 .for _t in ${_obj} build-tools
 	${_+_}cd ${.CURDIR}/${_dir}; \
diff --git a/share/mk/bsd.compat.mk b/share/mk/bsd.compat.mk
--- a/share/mk/bsd.compat.mk
+++ b/share/mk/bsd.compat.mk
@@ -95,34 +95,34 @@
 # Set defaults based on type.
 libcompat=	${_LIBCOMPAT:tl}
 _LIBCOMPAT_MAKEVARS=	_OBJTOP TMP CPUFLAGS CFLAGS CXXFLAGS LDFLAGS \
-			_MACHINE _MACHINE_ARCH WMAKEENV WMAKEFLAGS WMAKE
+			_MACHINE _MACHINE_ARCH \
+			WMAKEENV WMAKEFLAGS WMAKE WORLDTMP
 .for _var in ${_LIBCOMPAT_MAKEVARS}
 .if !empty(LIB${_LIBCOMPAT}${_var})
 LIBCOMPAT${_var}?=	${LIB${_LIBCOMPAT}${_var}}
 .endif
 .endfor
 
+WORLDTMP?=		${SYSROOT}
+
 # Shared flags
 LIBCOMPAT_OBJTOP?=	${OBJTOP}/obj-lib${libcompat}
-LIBCOMPATTMP?=		${LIBCOMPAT_OBJTOP}/tmp
 
 LIBCOMPATCFLAGS+=	${LIBCOMPATCPUFLAGS} \
-			--sysroot=${LIBCOMPATTMP} \
+			--sysroot=${WORLDTMP} \
 			${BFLAGS}
 
-LIBCOMPATLDFLAGS+=	-L${LIBCOMPATTMP}/usr/lib${libcompat}
+LIBCOMPATLDFLAGS+=	-L${WORLDTMP}/usr/lib${libcompat}
 
 LIBCOMPATWMAKEENV+=	MACHINE=${LIBCOMPAT_MACHINE}
 LIBCOMPATWMAKEENV+=	MACHINE_ARCH=${LIBCOMPAT_MACHINE_ARCH}
 
 # -B is needed to find /usr/lib32/crti.o for gcc.
-LIBCOMPATCFLAGS+=	-B${LIBCOMPATTMP}/usr/lib${libcompat}
+LIBCOMPATCFLAGS+=	-B${WORLDTMP}/usr/lib${libcompat}
 
 .if defined(WANT_COMPAT)
 LIBDIR_BASE:=	/usr/lib${libcompat}
 _LIB_OBJTOP=	${LIBCOMPAT_OBJTOP}
-LIBDESTDIR:=	${LIBCOMPATTMP}
-SYSROOT:=	${LIBCOMPATTMP}
 CFLAGS+=	${LIBCOMPATCFLAGS}
 LDFLAGS+=	${CFLAGS} ${LIBCOMPATLDFLAGS}
 MACHINE=	${LIBCOMPAT_MACHINE}