-CFLAGS += -DNOID -I${.CURDIR}/include -I${.CURDIR}/include/objc
-PRIVINC = ${NEXT_ROOT}/System/Library/Frameworks/System.framework/PrivateHeaders
-CFLAGS += -I${PRIVINC}
+CFLAGS += -DNOID
+.ifdef ALTLIBCHEADERS
+CFLAGS += -I${ALTLIBCHEADERS}
+.else
+CFLAGS += -I${.CURDIR}/include
+.endif
+.ifdef ALTFRAMEWORKSPATH
+PRIVINC = -F${ALTFRAMEWORKSPATH} -I${ALTFRAMEWORKSPATH}/System.framework/PrivateHeaders
+.else
+PRIVINC = -I${NEXT_ROOT}/System/Library/Frameworks/System.framework/PrivateHeaders
+.endif
+CFLAGS += ${PRIVINC}