diff --git a/maps/maps.go b/maps/maps.go
index f21e1a3..f145c2c 100644
--- a/maps/maps.go
+++ b/maps/maps.go
@@ -1,6 +1,8 @@
 package maps
 
 import (
+	"io/fs"
+	"os"
 	"path/filepath"
 	"sort"
 
@@ -26,3 +28,14 @@ func Keys[T any](m map[string]T) []string {
 func CleanPaths(paths []string) []string {
 	return fn.Map(paths, func(i string) string { return filepath.Clean(i) })
 }
+
+// MarkDirs will add an os.PathSeparator to the end of the name if the
+// fs.DirEntry is a directory.
+func MarkDirs(entries []fs.DirEntry) []string {
+	return fn.Map(entries, func(f fs.DirEntry) string {
+		if f.IsDir() {
+			return f.Name() + string(os.PathSeparator)
+		}
+		return f.Name()
+	})
+}
diff --git a/maps/maps_test.go b/maps/maps_test.go
index 38d81da..c8ee6b6 100644
--- a/maps/maps_test.go
+++ b/maps/maps_test.go
@@ -2,7 +2,9 @@ package maps_test
 
 import (
 	"fmt"
+	"os"
 
+	"github.com/rwxrob/bonzai/loop"
 	"github.com/rwxrob/bonzai/maps"
 )
 
@@ -30,10 +32,21 @@ func ExampleCleanPaths() {
 		`./thing`,
 		`/sub/../../thing`,
 	}
-	filter.Println(filter.CleanPaths(paths))
+
+	loop.Println(maps.CleanPaths(paths))
+
 	// Output:
 	// .
 	// .
 	// .
+	// thing
 	// /thing
 }
+
+func ExampleMarkDirs() {
+	entries, _ := os.ReadDir("testdata/markdirs")
+	loop.Println(maps.MarkDirs(entries))
+	//Output:
+	// dir1/
+	// file1
+}
diff --git a/maps/testdata/markdirs/file1 b/maps/testdata/markdirs/file1
new file mode 100644
index 0000000..e69de29