diff --git a/integration/integration_test.go b/integration/integration_test.go
index a8bc0661..1997f74d 100644
--- a/integration/integration_test.go
+++ b/integration/integration_test.go
@@ -1,7 +1,12 @@
 package integration
 
 import (
+	"bytes"
+	"io"
+	"os"
+	"os/exec"
 	"path/filepath"
+	"regexp"
 	"testing"
 
 	"github.com/cloudfoundry/dagger"
@@ -75,4 +80,41 @@ func testIntegration(t *testing.T, when spec.G, it spec.S) {
 			Expect(body).To(ContainSubstring("Package A value 2"))
 		})
 	})
+
+	when("the app is pushed twice", func() {
+		it("does not reinstall node_modules", func() {
+			appDir := filepath.Join("testdata", "simple_app")
+			app, err := dagger.PackBuild(appDir, nodeBP, bp)
+			Expect(err).ToNot(HaveOccurred())
+			defer app.Destroy()
+
+			Expect(app.BuildLogs()).To(MatchRegexp("node_modules .*: Contributing to layer"))
+
+			buildLogs := &bytes.Buffer{}
+
+			// TODO: Move this to dagger
+
+			_, imageID, _, err := app.Info()
+			Expect(err).NotTo(HaveOccurred())
+
+			cmd := exec.Command("pack", "build", imageID, "--builder", "cfbuildpacks/cflinuxfs3-cnb-test-builder", "--clear-cache", "--buildpack", nodeBP, "--buildpack", bp)
+			cmd.Dir = appDir
+			cmd.Stdout = io.MultiWriter(os.Stdout, buildLogs)
+			cmd.Stderr = io.MultiWriter(os.Stderr, buildLogs)
+			Expect(cmd.Run()).To(Succeed())
+
+			const ansi = "[\u001B\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[a-zA-Z\\d]*)*)?\u0007)|(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PRZcf-ntqry=><~]))"
+
+			re := regexp.MustCompile(ansi)
+			strippedLogs := re.ReplaceAllString(buildLogs.String(), "")
+
+			Expect(strippedLogs).To(MatchRegexp("node_modules .*: Reusing cached layer"))
+			Expect(strippedLogs).NotTo(MatchRegexp("node_modules .*: Contributing to layer"))
+
+			Expect(app.Start()).To(Succeed())
+
+			_, _, err = app.HTTPGet("/")
+			Expect(err).NotTo(HaveOccurred())
+		})
+	})
 }
diff --git a/modules/modules.go b/modules/modules.go
index 0b864008..d66dae93 100644
--- a/modules/modules.go
+++ b/modules/modules.go
@@ -83,7 +83,7 @@ func NewContributor(context build.Build, pkgManager PackageManager) (Contributor
 }
 
 func (c Contributor) Contribute() error {
-	return c.modulesLayer.Contribute(c.Metadata, func(layer layers.Layer) error {
+	if err := c.modulesLayer.Contribute(c.Metadata, func(layer layers.Layer) error {
 		offlineCache := filepath.Join(c.app.Root, "npm-packages-offline-cache")
 
 		modulesDir := filepath.Join(c.modulesLayer.Root, yarn.ModulesDir)
@@ -109,15 +109,6 @@ func (c Contributor) Contribute() error {
 			return fmt.Errorf("unable make layer: %s", err.Error())
 		}
 
-		//nodeModules := filepath.Join(c.app.Root, yarn.ModulesDir)
-		//if err := helper.CopyDirectory(nodeModules, filepath.Join(layer.Root, yarn.ModulesDir)); err != nil {
-		//	return fmt.Errorf(`unable to copy "%s" to "%s": %s`, nodeModules, layer.Root, err.Error())
-		//}
-
-		//if err := os.RemoveAll(nodeModules); err != nil {
-		//	return fmt.Errorf("unable to remove node_modules from the app dir: %s", err.Error())
-		//}
-
 		yarnCache := filepath.Join(c.app.Root, yarn.CacheDir)
 		if err := helper.CopyDirectory(yarnCache, filepath.Join(layer.Root, yarn.CacheDir)); err != nil {
 			return fmt.Errorf(`unable to copy "%s" to "%s": %s`, yarnCache, layer.Root, err.Error())
@@ -135,14 +126,14 @@ func (c Contributor) Contribute() error {
 			return err
 		}
 
-		if err := layer.OverrideSharedEnv("npm_config_nodedir", os.Getenv("NODE_HOME")); err != nil {
-			return err
-		}
+		return layer.OverrideSharedEnv("npm_config_nodedir", os.Getenv("NODE_HOME"))
+	}, c.flags()...); err != nil {
+		return err
+	}
 
-		return c.launchLayer.WriteApplicationMetadata(layers.Metadata{
-			Processes: []layers.Process{{"web", "yarn start"}},
-		})
-	}, c.flags()...)
+	return c.launchLayer.WriteApplicationMetadata(layers.Metadata{
+		Processes: []layers.Process{{"web", "yarn start"}},
+	})
 }
 
 func (c Contributor) flags() []layers.Flag {
diff --git a/scripts/install_tools.sh b/scripts/install_tools.sh
index 7d3b5400..856f9751 100755
--- a/scripts/install_tools.sh
+++ b/scripts/install_tools.sh
@@ -21,6 +21,8 @@ if [ "$#" -eq 1  ]; then
 fi
 
 install_pack() {
+    if [[ -f ".bin/pack" ]]; then return 0; fi
+
     OS=$(uname -s)
 
     if [[ $OS == "Darwin" ]]; then
@@ -75,11 +77,11 @@ expand() {
     rm $PACK_ARTIFACT
 }
 
-configure_pack() {
-    pack add-stack org.cloudfoundry.stacks.cflinuxfs3 \
-        --build-image cfbuildpacks/cflinuxfs3-cnb-experimental:build \
-        --run-image cfbuildpacks/cflinuxfs3-cnb-experimental:run || echo "Ignoring add stack error"
-}
+#configure_pack() {
+#    pack add-stack org.cloudfoundry.stacks.cflinuxfs3 \
+#        --build-image cfbuildpacks/cflinuxfs3-cnb-experimental:build \
+#        --run-image cfbuildpacks/cflinuxfs3-cnb-experimental:run || echo "Ignoring add stack error"
+#}
 
 cd "$( dirname "${BASH_SOURCE[0]}" )/.."
 
@@ -87,6 +89,6 @@ mkdir -p .bin
 export PATH=$(pwd)/.bin:$PATH
 
 install_pack
-configure_pack
+#configure_pack
 install_packager