diff --git a/Makefile b/Makefile
index da681d1..c691d1b 100644
--- a/Makefile
+++ b/Makefile
@@ -24,9 +24,9 @@ clean:
 
 build: clean
 	mkdir -p ${WRKDIR}
-	go build -ldflags="${LDFLAGS}" -o ${WRKDIR}/moncheck ${PKGNAME}/cmd/moncheck
-	go build -ldflags="${LDFLAGS}" -o ${WRKDIR}/monfront ${PKGNAME}/cmd/monfront
-	go build -ldflags="${LDFLAGS}" -o ${WRKDIR}/monwork ${PKGNAME}/cmd/monwork
+	GOOS=${GOOS} go build -ldflags="${LDFLAGS}" -o ${WRKDIR}/moncheck ${PKGNAME}/cmd/moncheck
+	GOOS=${GOOS} go build -ldflags="${LDFLAGS}" -o ${WRKDIR}/monfront ${PKGNAME}/cmd/monfront
+	GOOS=${GOOS} go build -ldflags="${LDFLAGS}" -o ${WRKDIR}/monwork ${PKGNAME}/cmd/monwork
 
 install: build
 	install -d -m 0755 ${DESTDIR}${bindir}