diff --git a/actions/review.go b/actions/review.go
index 7bc9e1c..9c41897 100644
--- a/actions/review.go
+++ b/actions/review.go
@@ -2,13 +2,11 @@ package actions
 
 import (
 	"bufio"
+	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
 	"net/http"
-	"os"
-	"os/user"
-	"path"
+	"os/exec"
 	"regexp"
 	"strings"
 	"text/tabwriter"
@@ -18,11 +16,9 @@ import (
 	"github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/config"
 	"github.com/go-git/go-git/v5/plumbing"
-	gitConfig "github.com/go-git/go-git/v5/plumbing/format/config"
 	"github.com/go-git/go-git/v5/plumbing/object"
 	"github.com/google/go-github/v32/github"
 	"github.com/pkg/errors"
-	"github.com/shibumi/go-pathspec"
 	"github.com/shurcooL/graphql"
 	"github.com/urfave/cli/v2"
 )
@@ -119,118 +115,25 @@ func Review(c *cli.Context) error {
 }
 
 func checkCleanWorktree(ctx context.Context, gitHubRepo *gitHubRepo) error {
-	worktree, err := gitHubRepo.GitRepo().Worktree()
-	if err != nil {
-		return errors.WithStack(err)
-	}
-	status, err := worktree.Status()
+	// Worktree.Status() is very slow so fall back to the command line instead.
+	// https://github.com/go-git/go-git/issues/181
+	cmd := exec.Command("git", "status", "--porcelain")
+	var stdout bytes.Buffer
+	cmd.Stdout = &stdout
+	err := cmd.Run()
 	if err != nil {
+		var exitErr exec.ExitError
+		if errors.As(err, &exitErr) {
+			return errors.Errorf("git status failed: %s", exitErr.Stderr)
+		}
 		return errors.WithStack(err)
 	}
-	if !status.IsClean() {
-		// go-git's handling of gitignore is not reliable, so we iterate over
-		// un-clean files again to make sure that files to be ignored are
-		// properly ignored based on the new ignore patterns.
-		ignorePatterns, err := getGitIgnorePatterns()
-		if err != nil {
-			return err
-		}
-		for filePath := range status {
-			match, err := pathspec.GitIgnore(ignorePatterns, filePath)
-			if err != nil {
-				return err
-			}
-			if match {
-				delete(status, filePath)
-			}
-		}
-		if len(status) > 0 {
-			return errors.Errorf("index is not clean:\n%v", status)
-		}
+	if stdout.Len() > 0 {
+		return errors.Errorf("index is not clean")
 	}
 	return nil
 }
 
-// getGitIgnorePatterns returns all patterns to ignore for a given project,
-// by looking at the project's gitignore, global gitignore, and system gitignore
-func getGitIgnorePatterns() ([]string, error) {
-	var ignorePatterns []string
-	projectIgnorePatterns, err := getIgnorePatterns("./.gitignore")
-	if err != nil {
-		return nil, err
-	}
-	ignorePatterns = append(ignorePatterns, projectIgnorePatterns...)
-	currentUser, err := user.Current()
-	if err != nil {
-		return nil, err
-	}
-	globalIgnorePath, err := getIgnoreFilePathFromConfig(path.Join(currentUser.HomeDir, ".gitconfig"))
-	if err != nil && !os.IsNotExist(err) {
-		return nil, err
-	}
-	globalIgnorePatterns, err := getIgnorePatterns(globalIgnorePath)
-	if err != nil {
-		return nil, err
-	}
-	ignorePatterns = append(ignorePatterns, globalIgnorePatterns...)
-	systemIgnorePath, err := getIgnoreFilePathFromConfig("/etc/gitconfig")
-	if err != nil && !os.IsNotExist(err) {
-		return nil, err
-	}
-	systemIgnorePatterns, err := getIgnorePatterns(systemIgnorePath)
-	if err != nil {
-		return nil, err
-	}
-	ignorePatterns = append(ignorePatterns, systemIgnorePatterns...)
-	var allPatterns []string
-	for _, pattern := range ignorePatterns {
-		allPatterns = append(allPatterns, pattern)
-		// for any pattern that has no wildcard and slash, add a slash at the end
-		// to make sure that a new rule is added that every file in a directory
-		// is ignored. this is to handle go-git's behaviour where certain files
-		// are not ignored (e.g., node_modules/dist/.gitkeep is not ignored even
-		// when there is a pattern `node_modules` in gitignore file.
-		if !strings.Contains(pattern, "**") &&
-			!strings.HasPrefix(pattern, "/") &&
-			!strings.HasSuffix(pattern, "/") {
-			allPatterns = append(allPatterns, pattern, pattern+"/")
-		}
-	}
-	return allPatterns, nil
-}
-
-// getIgnoreFilePathFromConfig returns path to a gitignore file,
-// specified given config file
-func getIgnoreFilePathFromConfig(configPath string) (string, error) {
-	configContent, err := os.Open(configPath)
-	if err != nil {
-		return "", err
-	}
-	decoder := gitConfig.NewDecoder(configContent)
-	raw := gitConfig.New()
-	if err = decoder.Decode(raw); err != nil {
-		return "", err
-	}
-	configSection := raw.Section("core")
-	return configSection.Options.Get("excludesfile"), nil
-}
-
-// getIgnorePatterns reads a gitignore file and returns its list of patterns
-// in a slice of strings
-func getIgnorePatterns(filePath string) ([]string, error) {
-	content, err := ioutil.ReadFile(filePath)
-	if err != nil && !os.IsNotExist(err) {
-		return []string{}, err
-	}
-	var patterns []string
-	for _, pattern := range strings.Split(string(content), "\n") {
-		if pattern != "" {
-			patterns = append(patterns, pattern)
-		}
-	}
-	return patterns, nil
-}
-
 func getReviewInfo(
 	ctx context.Context,
 	gitHubRepo *gitHubRepo,
diff --git a/go.mod b/go.mod
index c819540..3037f1f 100644
--- a/go.mod
+++ b/go.mod
@@ -8,7 +8,6 @@ require (
 	github.com/go-git/go-git/v5 v5.3.0
 	github.com/google/go-github/v32 v32.1.0
 	github.com/pkg/errors v0.9.1
-	github.com/shibumi/go-pathspec v1.2.0
 	github.com/shurcooL/graphql v0.0.0-20181231061246-d48a9a75455f
 	github.com/urfave/cli/v2 v2.2.0
 	github.com/zalando/go-keyring v0.1.1
diff --git a/go.sum b/go.sum
index 7039a2b..88b27d0 100644
--- a/go.sum
+++ b/go.sum
@@ -13,8 +13,6 @@ github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239/go.mod h1:2FmKhYU
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5/go.mod h1:wHh0iHkYZB8zMSxRWpUBQtwG5a7fFgvEO+odwuTv2gs=
 github.com/cli/browser v1.0.0/go.mod h1:IEWkHYbLjkhtjwwWlwTHW2lGxeS5gezEQBMLTwDHf5Q=
-github.com/cli/oauth v0.8.0 h1:YTFgPXSTvvDUFti3tR4o6q7Oll2SnQ9ztLwCAn4/IOA=
-github.com/cli/oauth v0.8.0/go.mod h1:qd/FX8ZBD6n1sVNQO3aIdRxeu5LGw9WhKnYhIIoC2A4=
 github.com/cli/oauth v0.9.0 h1:nxBC0Df4tUzMkqffAB+uZvisOwT3/N9FpkfdTDtafxc=
 github.com/cli/oauth v0.9.0/go.mod h1:qd/FX8ZBD6n1sVNQO3aIdRxeu5LGw9WhKnYhIIoC2A4=
 github.com/cli/safeexec v1.0.0/go.mod h1:Z/D4tTN8Vs5gXYHDCbaM1S/anmEDnJb1iW0+EJ5zx3Q=
@@ -90,8 +88,6 @@ github.com/russross/blackfriday/v2 v2.0.1 h1:lPqVAte+HuHNfhJ/0LC98ESWRz8afy9tM/0
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/sergi/go-diff v1.1.0 h1:we8PVUC3FE2uYfodKH/nBHMSetSfHDR6scGdBi+erh0=
 github.com/sergi/go-diff v1.1.0/go.mod h1:STckp+ISIX8hZLjrqAeVduY0gWCT9IjLuqbuNXdaHfM=
-github.com/shibumi/go-pathspec v1.2.0 h1:KVKEDHYk7bQolRMs7nfzjT3SBOCgcXFJzccnj9bsGbA=
-github.com/shibumi/go-pathspec v1.2.0/go.mod h1:bDxCftD0fST3qXIlHoQ/fChsU4mWMVklXp1yPErQaaY=
 github.com/shurcooL/graphql v0.0.0-20181231061246-d48a9a75455f h1:tygelZueB1EtXkPI6mQ4o9DQ0+FKW41hTbunoXZCTqk=
 github.com/shurcooL/graphql v0.0.0-20181231061246-d48a9a75455f/go.mod h1:AuYgA5Kyo4c7HfUmvRGs/6rGlMMV/6B1bVnB9JxJEEg=
 github.com/shurcooL/sanitized_anchor_name v1.0.0 h1:PdmoCO6wvbs+7yrJyMORt4/BmY5IYyJwS/kOiWx8mHo=
@@ -131,7 +127,6 @@ golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200302150141-5c8b2ff67527/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210324051608-47abb6519492 h1:Paq34FxTluEPvVyayQqMPgHm+vTOrIifmcYxFBx9TLg=
 golang.org/x/sys v0.0.0-20210324051608-47abb6519492/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210616045830-e2b7044e8c71 h1:X/2sJAybVknnUnV7AD2HdT6rm2p5BP6eH2j+igduWgk=
 golang.org/x/sys v0.0.0-20210616045830-e2b7044e8c71/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=