diff --git a/.github/workflows/build-test.yml b/.github/workflows/build-test.yml
index 9503674ed..b2bf21776 100644
--- a/.github/workflows/build-test.yml
+++ b/.github/workflows/build-test.yml
@@ -32,5 +32,7 @@ jobs:
         run: go mod tidy -diff
       - name: Run unit tests
         run: make test-coverage
+      - name: Test ignore rules with the race detector
+        run: go test -race ./pkg/ignore
       - name: Test build
         run: make build
diff --git a/pkg/ignore/rules.go b/pkg/ignore/rules.go
index a8160da2a..17fcf6306 100644
--- a/pkg/ignore/rules.go
+++ b/pkg/ignore/rules.go
@@ -172,8 +172,8 @@ func (r *Rules) parseRule(rule string) error {
 
 	if after, ok := strings.CutPrefix(rule, "/"); ok {
 		// Require path matches the root path.
+		rule = after
 		p.match = func(n string, _ os.FileInfo) bool {
-			rule = after
 			ok, err := filepath.Match(rule, n)
 			if err != nil {
 				slog.Error("failed to compile", slog.String("rule", rule), slog.Any("error", err))
diff --git a/pkg/ignore/rules_test.go b/pkg/ignore/rules_test.go
index 30e157a52..310daca43 100644
--- a/pkg/ignore/rules_test.go
+++ b/pkg/ignore/rules_test.go
@@ -20,6 +20,7 @@ import (
 	"bytes"
 	"os"
 	"path/filepath"
+	"sync"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -133,3 +134,19 @@ func parseString(str string) (*Rules, error) {
 	b := bytes.NewBuffer([]byte(str))
 	return Parse(b)
 }
+
+func TestIgnoreRootPatternConcurrent(t *testing.T) {
+	// Run with -race to detect concurrent writes even when matching results agree.
+	rules, err := parseString("/root.txt")
+	require.NoError(t, err)
+	var workers sync.WaitGroup
+	for range 8 {
+		workers.Go(func() {
+			for range 100 {
+				assert.True(t, rules.Ignore("root.txt", nil))
+				assert.False(t, rules.Ignore("nested/root.txt", nil))
+			}
+		})
+	}
+	workers.Wait()
+}