diff --git a/pkg/build/gobuild.go b/pkg/build/gobuild.go
index 9f21dfd9fe..2c7aa10b2e 100644
--- a/pkg/build/gobuild.go
+++ b/pkg/build/gobuild.go
@@ -27,6 +27,7 @@ import (
 	"log"
 	"os"
 	"os/exec"
+	"path"
 	"path/filepath"
 	"strings"
 
@@ -237,7 +238,7 @@ func tarBinary(name, binary string) (*bytes.Buffer, error) {
 	defer tw.Close()
 
 	// write the parent directories to the tarball archive
-	if err := tarAddDirectories(tw, filepath.Dir(name)); err != nil {
+	if err := tarAddDirectories(tw, path.Dir(name)); err != nil {
 		return nil, err
 	}
 
@@ -286,8 +287,8 @@ const kodataRoot = "/var/run/ko"
 // to the provided tar.Writer with root -> chroot.  All symlinks are dereferenced,
 // which is what leads to recursion when we encounter a directory symlink.
 func walkRecursive(tw *tar.Writer, root, chroot string) error {
-	return filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
-		if path == root {
+	return filepath.Walk(root, func(hostPath string, info os.FileInfo, err error) error {
+		if hostPath == root {
 			// Add an entry for the root directory of our walk.
 			return tw.WriteHeader(&tar.Header{
 				Name:     chroot,
@@ -305,25 +306,25 @@ func walkRecursive(tw *tar.Writer, root, chroot string) error {
 		if info.Mode().IsDir() {
 			return nil
 		}
-		newPath := filepath.Join(chroot, path[len(root):])
+		newPath := path.Join(chroot, filepath.ToSlash(hostPath[len(root):]))
 
-		path, err = filepath.EvalSymlinks(path)
+		hostPath, err = filepath.EvalSymlinks(hostPath)
 		if err != nil {
 			return err
 		}
 
 		// Chase symlinks.
-		info, err = os.Stat(path)
+		info, err = os.Stat(hostPath)
 		if err != nil {
 			return err
 		}
 		// Skip other directories.
 		if info.Mode().IsDir() {
-			return walkRecursive(tw, path, newPath)
+			return walkRecursive(tw, hostPath, newPath)
 		}
 
 		// Open the file to copy it into the tarball.
-		file, err := os.Open(path)
+		file, err := os.Open(hostPath)
 		if err != nil {
 			return err
 		}
@@ -411,7 +412,7 @@ func (gb *gobuild) Build(ctx context.Context, s string) (v1.Image, error) {
 		},
 	})
 
-	appPath := filepath.Join(appDir, appFilename(s))
+	appPath := path.Join(appDir, appFilename(s))
 
 	// Construct a tarball with the binary and produce a layer.
 	binaryLayerBuf, err := tarBinary(appPath, file)
diff --git a/pkg/build/gobuild_test.go b/pkg/build/gobuild_test.go
index a7292313d8..9888e7050c 100644
--- a/pkg/build/gobuild_test.go
+++ b/pkg/build/gobuild_test.go
@@ -19,6 +19,7 @@ import (
 	"context"
 	"io"
 	"io/ioutil"
+	"path"
 	"path/filepath"
 	"testing"
 	"time"
@@ -40,7 +41,7 @@ func TestGoBuildIsSupportedRef(t *testing.T) {
 
 	// Supported import paths.
 	for _, importpath := range []string{
-		filepath.FromSlash("github.com/google/ko/cmd/ko"), // ko can build itself.
+		"github.com/google/ko/cmd/ko", // ko can build itself.
 	} {
 		t.Run(importpath, func(t *testing.T) {
 			if !ng.IsSupportedReference(importpath) {
@@ -51,8 +52,8 @@ func TestGoBuildIsSupportedRef(t *testing.T) {
 
 	// Unsupported import paths.
 	for _, importpath := range []string{
-		filepath.FromSlash("github.com/google/ko/pkg/build"),       // not a command.
-		filepath.FromSlash("github.com/google/ko/pkg/nonexistent"), // does not exist.
+		"github.com/google/ko/pkg/build",       // not a command.
+		"github.com/google/ko/pkg/nonexistent", // does not exist.
 	} {
 		t.Run(importpath, func(t *testing.T) {
 			if ng.IsSupportedReference(importpath) {
@@ -68,7 +69,7 @@ func TestGoBuildIsSupportedRefWithModules(t *testing.T) {
 		t.Fatalf("random.Image() = %v", err)
 	}
 	mod := &modInfo{
-		Path: filepath.FromSlash("github.com/google/ko/cmd/ko/test"),
+		Path: "github.com/google/ko/cmd/ko/test",
 		Dir:  ".",
 	}
 
@@ -79,7 +80,7 @@ func TestGoBuildIsSupportedRefWithModules(t *testing.T) {
 
 	// Supported import paths.
 	for _, importpath := range []string{
-		filepath.FromSlash("github.com/google/ko/cmd/ko/test"), // ko can build the test package.
+		"github.com/google/ko/cmd/ko/test", // ko can build the test package.
 	} {
 		t.Run(importpath, func(t *testing.T) {
 			if !ng.IsSupportedReference(importpath) {
@@ -90,9 +91,9 @@ func TestGoBuildIsSupportedRefWithModules(t *testing.T) {
 
 	// Unsupported import paths.
 	for _, importpath := range []string{
-		filepath.FromSlash("github.com/google/ko/pkg/build"),       // not a command.
-		filepath.FromSlash("github.com/google/ko/pkg/nonexistent"), // does not exist.
-		filepath.FromSlash("github.com/google/ko/cmd/ko"),          // not in this module.
+		"github.com/google/ko/pkg/build",       // not a command.
+		"github.com/google/ko/pkg/nonexistent", // does not exist.
+		"github.com/google/ko/cmd/ko",          // not in this module.
 	} {
 		t.Run(importpath, func(t *testing.T) {
 			if ng.IsSupportedReference(importpath) {
@@ -138,7 +139,7 @@ func TestGoBuildNoKoData(t *testing.T) {
 		t.Fatalf("NewGo() = %v", err)
 	}
 
-	img, err := ng.Build(context.Background(), filepath.Join(importpath, "cmd", "ko"))
+	img, err := ng.Build(context.Background(), path.Join(importpath, "cmd", "ko"))
 	if err != nil {
 		t.Fatalf("Build() = %v", err)
 	}
@@ -218,7 +219,7 @@ func TestGoBuild(t *testing.T) {
 		t.Fatalf("NewGo() = %v", err)
 	}
 
-	img, err := ng.Build(context.Background(), filepath.Join(importpath, "cmd", "ko", "test"))
+	img, err := ng.Build(context.Background(), path.Join(importpath, "cmd", "ko", "test"))
 	if err != nil {
 		t.Fatalf("Build() = %v", err)
 	}
@@ -290,7 +291,7 @@ func TestGoBuild(t *testing.T) {
 				t.Errorf("Next() = %v", err)
 				continue
 			}
-			if header.Name != filepath.Join(kodataRoot, "kenobi") {
+			if header.Name != path.Join(kodataRoot, "kenobi") {
 				continue
 			}
 			found = true