diff --git a/iso_639-1.go b/iso_639-1.go
index 2dadb66..45cb767 100644
--- a/iso_639-1.go
+++ b/iso_639-1.go
@@ -2,6 +2,8 @@ package iso639
 
 import (
 	"fmt"
+
+	"git.0x0001f346.de/andreas/utils"
 )
 
 var iso639_1CodeToName = map[string]string{
@@ -378,12 +380,12 @@ var iso639_1NameToCode = map[string]string{
 
 // GetAllISO639_1Codes returns all ISO 639-1 codes
 func GetAllISO639_1Codes() []string {
-	return getAllKeysOfMap(iso639_1CodeToName)
+	return utils.GetAllStringKeysOfMap(iso639_1CodeToName)
 }
 
 // GetAllISO639_1Names returns all ISO 639-1 language names
 func GetAllISO639_1Names() []string {
-	return getAllKeysOfMap(iso639_1NameToCode)
+	return utils.GetAllStringKeysOfMap(iso639_1NameToCode)
 }
 
 // GetISO639_1CodeForLanguageName tries to match a language name to an ISO 639-1 code
diff --git a/iso_639-2b.go b/iso_639-2b.go
index 74adb1f..6add215 100644
--- a/iso_639-2b.go
+++ b/iso_639-2b.go
@@ -2,6 +2,8 @@ package iso639
 
 import (
 	"fmt"
+
+	"git.0x0001f346.de/andreas/utils"
 )
 
 var iso639_2BCodeToName = map[string]string{
@@ -378,12 +380,12 @@ var iso639_2BNameToCode = map[string]string{
 
 // GetAllISO639_2BCodes returns all ISO 639-2/B codes
 func GetAllISO639_2BCodes() []string {
-	return getAllKeysOfMap(iso639_2BCodeToName)
+	return utils.GetAllStringKeysOfMap(iso639_2BCodeToName)
 }
 
 // GetAllISO639_2BNames returns all ISO 639-2/B language names
 func GetAllISO639_2BNames() []string {
-	return getAllKeysOfMap(iso639_2BNameToCode)
+	return utils.GetAllStringKeysOfMap(iso639_2BNameToCode)
 }
 
 // GetISO639_2BCodeForLanguageName tries to match a language name to an ISO 639-2/B code
diff --git a/iso_639-2t.go b/iso_639-2t.go
index 718939f..f9bdce0 100644
--- a/iso_639-2t.go
+++ b/iso_639-2t.go
@@ -2,6 +2,8 @@ package iso639
 
 import (
 	"fmt"
+
+	"git.0x0001f346.de/andreas/utils"
 )
 
 var iso639_2TCodeToName = map[string]string{
@@ -378,12 +380,12 @@ var iso639_2TNameToCode = map[string]string{
 
 // GetAllISO639_2TCodes returns all ISO 639-2/T codes
 func GetAllISO639_2TCodes() []string {
-	return getAllKeysOfMap(iso639_2TCodeToName)
+	return utils.GetAllStringKeysOfMap(iso639_2TCodeToName)
 }
 
 // GetAllISO639_2TNames returns all ISO 639-2/T language names
 func GetAllISO639_2TNames() []string {
-	return getAllKeysOfMap(iso639_2TNameToCode)
+	return utils.GetAllStringKeysOfMap(iso639_2TNameToCode)
 }
 
 // GetISO639_2TCodeForLanguageName tries to match a language name to an ISO 639-2/T code
diff --git a/iso_639.go b/iso_639.go
index 88c5e8d..ee70218 100644
--- a/iso_639.go
+++ b/iso_639.go
@@ -2,7 +2,6 @@ package iso639
 
 import (
 	"fmt"
-	"sort"
 )
 
 // GetLanguageNameForISO639Code tries get the language name for an ISO 639-1, ISO 639-2/B or ISO 639-2/T code
@@ -24,15 +23,3 @@ func GetLanguageNameForISO639Code(s string) (string, error) {
 
 	return "", fmt.Errorf("no language name found for ISO 639 code: %s", s)
 }
-
-func getAllKeysOfMap(m map[string]string) []string {
-	keys := make([]string, 0, len(m))
-
-	for key := range m {
-		keys = append(keys, key)
-	}
-
-	sort.Strings(keys)
-
-	return keys
-}
diff --git a/iso_639_test.go b/iso_639_test.go
index f891503..4d06ae5 100644
--- a/iso_639_test.go
+++ b/iso_639_test.go
@@ -2,30 +2,6 @@ package iso639
 
 import "testing"
 
-func TestGetAllKeysOfMap(t *testing.T) {
-	got := getAllKeysOfMap(
-		map[string]string{
-			"This":   "is",
-			"just":   "a",
-			"little": "test",
-			"for":    "you",
-		},
-	)
-
-	want := []string{
-		"This",
-		"for",
-		"just",
-		"little",
-	}
-
-	for i := 0; i <= 3; i++ {
-		if got[i] != want[i] {
-			t.Errorf("got %q, wanted %q", got[i], want[i])
-		}
-	}
-}
-
 func TestGetLanguageNameForISO639Code(t *testing.T) {
 	data := map[string]string{
 		"nl":         "Dutch", // ISO 639-1