diff --git a/Makefile b/Makefile
index f823be8107..586a6fcd3d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,3 @@
-DOCKER_OSX_IMAGE := osx-installer
-DOCKER_WINDOWS_IMAGE := windows-installer
-DOCKER_OSX_CONTAINER := build-osx-installer
-DOCKER_WINDOWS_CONTAINER := build-windows-installer
-
 default: osx windows
 	@true
 
@@ -10,23 +5,13 @@ clean: clean-osx clean-windows
 	@true
 
 osx: clean-osx
-	docker build -t $(DOCKER_OSX_IMAGE) -f Dockerfile.osx .
-	docker run --name "$(DOCKER_OSX_CONTAINER)" "$(DOCKER_OSX_IMAGE)"
-	mkdir -p dist
-	docker cp "$(DOCKER_OSX_CONTAINER)":/DockerToolbox.pkg dist/
-	docker rm "$(DOCKER_OSX_CONTAINER)" 2>/dev/null || true
+	./script/build-osx
 
 windows: clean-windows
-	docker build -t $(DOCKER_WINDOWS_IMAGE) -f Dockerfile.windows .
-	docker run --name "$(DOCKER_WINDOWS_CONTAINER)" "$(DOCKER_WINDOWS_IMAGE)"
-	mkdir -p dist
-	docker cp "$(DOCKER_WINDOWS_CONTAINER)":/installer/Output/DockerToolbox.exe dist/
-	docker rm "$(DOCKER_WINDOWS_CONTAINER)" 2>/dev/null || true
+	./script/build-windows
 
 clean-osx:
-	rm -f DockerToolbox-*.pkg
-	docker rm "$(DOCKER_OSX_CONTAINER)" 2>/dev/null || true
+	rm -f dist/DockerToolbox-*.pkg
 
 clean-windows:
-	rm -f DockerToolbox-*.exe
-	docker rm "$(DOCKER_WINDOWS_CONTAINER)" 2>/dev/null || true
+	rm -f dist/DockerToolbox-*.exe
diff --git a/script/build-osx b/script/build-osx
new file mode 100755
index 0000000000..05e44daf79
--- /dev/null
+++ b/script/build-osx
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+docker build -t osx-installer -f Dockerfile.osx .
+CONTAINER="$(docker run -d osx-installer)"
+mkdir -p dist
+docker cp "${CONTAINER}":/DockerToolbox.pkg dist/
+docker rm "${CONTAINER}" 2>/dev/null || true
diff --git a/script/build-windows b/script/build-windows
new file mode 100755
index 0000000000..93c9e75ee7
--- /dev/null
+++ b/script/build-windows
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+docker build -t windows-installer -f Dockerfile.windows .
+CONTAINER="$(docker run -d windows-installer)"
+mkdir -p dist
+docker cp "${CONTAINER}":/installer/Output/DockerToolbox.exe dist/
+docker rm "${CONTAINER}" 2>/dev/null || true