diff --git a/audformat/core/utils.py b/audformat/core/utils.py
index 1b6814c0..da113188 100644
--- a/audformat/core/utils.py
+++ b/audformat/core/utils.py
@@ -8,6 +8,7 @@
 import typing as typing
 
 import iso639
+from iso639.exceptions import InvalidLanguageValue
 import iso3166
 import numpy as np
 import pandas as pd
@@ -1288,32 +1289,13 @@ def map_language(language: str) -> str:
         'eng'
 
     """
-    result = None
-
-    if len(language) == 2:
-        try:
-            result = iso639.languages.get(alpha2=language.lower())
-        except KeyError:
-            pass
-    elif len(language) == 3:
-        try:
-            result = iso639.languages.get(part3=language.lower())
-        except KeyError:
-            pass
-    else:
-        try:
-            result = iso639.languages.get(name=language.title())
-        except KeyError:
-            pass
-
-    if result is not None:
-        result = result.part3
-
-    if not result:
+    try:
+        return iso639.Lang(
+            language.title() if len(language) > 3 else language.lower()
+        ).pt3
+    except InvalidLanguageValue:
         raise ValueError(f"'{language}' is not supported by ISO 639-3.")
 
-    return result
-
 
 def read_csv(
     *args,
diff --git a/pyproject.toml b/pyproject.toml
index 37637e36..c699f2c5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,7 +33,7 @@ requires-python = '>=3.9'  # pandas >=2.1.0
 dependencies = [
     'audeer >=2.0.0',
     'audiofile >=0.4.0',
-    'iso-639',
+    'iso639-lang',
     'iso3166',
     'oyaml',
     'pandas >=2.1.0',  # for pyarrow -> timedelta conversion