diff --git a/filter/filter.go b/filter/filter.go
index 930f5f7..98a2881 100644
--- a/filter/filter.go
+++ b/filter/filter.go
@@ -75,3 +75,12 @@ func Keys[T any](m map[string]T) []string {
 	}
 	return keys
 }
+
+// Prefix returns a new slice with prefix added to each string.
+func Prefix(in []string, pre string) []string {
+	list := []string{}
+	for _, i := range in {
+		list = append(list, pre+i)
+	}
+	return list
+}
diff --git a/filter/filter_test.go b/filter/filter_test.go
index e02576a..d1b47d4 100644
--- a/filter/filter_test.go
+++ b/filter/filter_test.go
@@ -50,3 +50,9 @@ func ExampleKeys() {
 	// [one three two]
 	// [one three two]
 }
+
+func ExamplePrefix() {
+	fmt.Println(filter.Prefix([]string{"foo", "bar"}, "my"))
+	// Output:
+	// [myfoo mybar]
+}