diff --git a/src/remote/fs/fs.go b/src/remote/fs/fs.go
index a26d89fb68..c239bac1a6 100644
--- a/src/remote/fs/fs.go
+++ b/src/remote/fs/fs.go
@@ -186,8 +186,8 @@ type dir struct {
 	*info
 }
 
-// ReadDir is a slightly incorrect implementation of ReadDir. It deviates slightly as it will report all files have 0
-// size. This seems to work for our limited purposes though.
+// ReadDir implements listing the contents of a directory stored in the CAS. This is entirely based off the original
+// data from the Tree proto so doesn't do any additional fetching.
 func (p *dir) ReadDir(n int) ([]iofs.DirEntry, error) {
 	dirSize := n
 	if n <= 0 {
diff --git a/src/remote/fs/fs_test.go b/src/remote/fs/fs_test.go
index 31889b75c1..25d07593ed 100644
--- a/src/remote/fs/fs_test.go
+++ b/src/remote/fs/fs_test.go
@@ -13,6 +13,8 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+var fooContent = "wibble wibble wibble"
+
 type fakeClient struct {
 	results map[digest.Digest][]byte
 }
@@ -39,8 +41,7 @@ func newDigest(str string) digest.Digest {
 //	|- badlink (a symlink to ../../foo which is root/.. i.e. invalid)
 func getTree(t *testing.T) (*fakeClient, *pb.Tree) {
 	t.Helper()
-
-	fooDigest := newDigest("foo")
+	fooDigest := newDigest(fooContent)
 
 	foo := &pb.FileNode{
 		Name: "foo",
@@ -120,7 +121,7 @@ func getTree(t *testing.T) (*fakeClient, *pb.Tree) {
 
 	fc := &fakeClient{
 		results: map[digest.Digest][]byte{
-			fooDigest: []byte("wibble wibble wibble"),
+			fooDigest: []byte(fooContent),
 		},
 	}
 	tree := &pb.Tree{
@@ -146,6 +147,9 @@ func TestReadDir(t *testing.T) {
 		require.NoError(t, err)
 		// We set them all to 0777 above
 		assert.Equal(t, iofs.FileMode(0777), i.Mode(), "%v mode was wrong", e.Name())
+		if e.Name() == "foo" {
+			assert.Equal(t, len([]byte(fooContent)), int(i.Size()))
+		}
 	}
 
 	entries, err = iofs.ReadDir(fs, ".")