diff --git a/mk/build.mk b/mk/build.mk
index cf45c69944..431052b09e 100644
--- a/mk/build.mk
+++ b/mk/build.mk
@@ -1,22 +1,23 @@
 extension = $(patsubst windows,.exe,$(filter windows,$(1)))
 
 define gocross
-	GOOS=$(1) GOARCH=$(2) CGO_ENABLED=0 $(GO) build \
-		-o $(PREFIX)/bin/docker-$(patsubst cmd/%.go,%,$3)_$(1)-$(2)$(call extension,$(GOOS)) \
+	GOOS=$(1) GOARCH=$(2) CGO_ENABLED=0 \
+		$(GO) build \
+		-o $(PREFIX)/bin/docker-machine_$(1)-$(2)$(call extension,$(GOOS)) \
 		-a $(VERBOSE_GO) -tags "static_build netgo $(BUILDTAGS)" -installsuffix netgo \
-		-ldflags "$(GO_LDFLAGS) -extldflags -static" $(GO_GCFLAGS) $(3);
+		-ldflags "$(GO_LDFLAGS) -extldflags -static" $(GO_GCFLAGS) ./cmd/machine.go;
 endef
 
 build-clean:
 	rm -Rf $(PREFIX)/bin/*
 
-build-x: ./cmd/machine.go
-	$(foreach GOARCH,$(TARGET_ARCH),$(foreach GOOS,$(TARGET_OS),$(call gocross,$(GOOS),$(GOARCH),$<)))
+build-x: $(shell find . -type f -name '*.go')
+	$(foreach GOARCH,$(TARGET_ARCH),$(foreach GOOS,$(TARGET_OS),$(call gocross,$(GOOS),$(GOARCH))))
 
-$(PREFIX)/bin/docker-machine$(call extension,$(GOOS)): ./cmd/machine.go
+$(PREFIX)/bin/docker-machine$(call extension,$(GOOS)): $(shell find . -type f -name '*.go')
 	$(GO) build \
 	-o $@ \
 	$(VERBOSE_GO) -tags "$(BUILDTAGS)" \
-	-ldflags "$(GO_LDFLAGS)" $(GO_GCFLAGS) $<
+	-ldflags "$(GO_LDFLAGS)" $(GO_GCFLAGS) ./cmd/machine.go
 
-build: $(PREFIX)/bin/docker-machine
+build: $(PREFIX)/bin/docker-machine$(call extension,$(GOOS))