diff --git a/walk/trie.go b/walk/trie.go
index 3371e7f26..0271db823 100644
--- a/walk/trie.go
+++ b/walk/trie.go
@@ -43,26 +43,12 @@ func (t *pathTrie) Get(key string) *pathTrie {
 	return node
 }
 
-func (t *pathTrie) Put(key string, entry *fs.DirEntry) bool {
-	node := t
-	for part, i := pathSegmenter(key, 0); part != ""; part, i = pathSegmenter(key, i) {
-		child := node.children[part]
-		if child == nil {
-			if node.children == nil {
-				node.children = map[string]*pathTrie{}
-			}
-
-			var child *pathTrie
-			if i < 0 {
-				child = &pathTrie{children: nil, entry: entry}
-			} else {
-				child = &pathTrie{}
-			}
-
-			node.children[part] = child
-		}
-		node = child
+func (t *pathTrie) AddChild(entry fs.DirEntry) *pathTrie {
+	if t.children == nil {
+		t.children = map[string]*pathTrie{}
 	}
 
-	return true
+	child := &pathTrie{entry: &entry}
+	t.children[entry.Name()] = child
+	return child
 }
diff --git a/walk/walk.go b/walk/walk.go
index fcad3c7c9..6312def83 100644
--- a/walk/walk.go
+++ b/walk/walk.go
@@ -25,7 +25,6 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
-	"sync"
 
 	"github.com/bazelbuild/bazel-gazelle/config"
 	"github.com/bazelbuild/bazel-gazelle/rule"
@@ -368,25 +367,18 @@ func resolveFileInfo(wc *walkConfig, dir, rel string, ent fs.DirEntry) fs.DirEnt
 
 func buildTrie(c *config.Config, isIgnored isIgnoredFunc) (*pathTrie, error) {
 	trie := &pathTrie{}
-	mu := sync.Mutex{}
 
 	eg := errgroup.Group{}
 	eg.SetLimit(100)
 	eg.Go(func() error {
-		return walkDir(c.RepoRoot, "", &eg, isIgnored, func(rel string, d fs.DirEntry) {
-			mu.Lock()
-			defer mu.Unlock()
-			trie.Put(rel, &d)
-		})
+		return walkDir(c.RepoRoot, "", &eg, isIgnored, trie)
 	})
 
 	return trie, eg.Wait()
 }
 
-type walkDirFunc func(rel string, d fs.DirEntry)
-
 // walkDir recursively descends path, calling walkDirFn.
-func walkDir(root, rel string, eg *errgroup.Group, isIgnored isIgnoredFunc, walkDirFn walkDirFunc) error {
+func walkDir(root, rel string, eg *errgroup.Group, isIgnored isIgnoredFunc, trie *pathTrie) error {
 	dirs, err := os.ReadDir(path.Join(root, rel))
 	if err != nil {
 		return err
@@ -401,11 +393,11 @@ func walkDir(root, rel string, eg *errgroup.Group, isIgnored isIgnoredFunc, walk
 			continue
 		}
 
-		walkDirFn(path1, d1)
+		childTrie := trie.AddChild(d1)
 
 		if d1.IsDir() {
 			eg.Go(func() error {
-				return walkDir(root, path1, eg, isIgnored, walkDirFn)
+				return walkDir(root, path1, eg, isIgnored, childTrie)
 			})
 		}
 	}