diff --git a/README.rst b/README.rst
index 9ca16ee..23814c2 100644
--- a/README.rst
+++ b/README.rst
@@ -221,6 +221,10 @@ To work around API limitation, you must first generate a
 Changes
 =======
 
+4.0 (2023-07-22)
+----------------
+
+* [BREAKING] drop support for other configuration file formats than yaml
 * Ensure git pull is always done in fast-forward mode
 
 3.0.1 (2022-09-21)
diff --git a/git_aggregator/config.py b/git_aggregator/config.py
index 8a3af96..0043e84 100644
--- a/git_aggregator/config.py
+++ b/git_aggregator/config.py
@@ -6,7 +6,8 @@
 import os
 from string import Template
 
-import kaptan
+import yaml
+
 from .exception import ConfigException
 from ._compat import string_types
 
@@ -148,7 +149,11 @@ def load_config(config, expand_env=False, env_file=None, force=False):
         raise ConfigException('Unable to find configuration file: %s' % config)
 
     file_extension = os.path.splitext(config)[1][1:]
-    conf = kaptan.Kaptan(handler=kaptan.HANDLER_EXT.get(file_extension))
+    if file_extension not in ("yaml", "yml"):
+        raise ConfigException(
+            "Only .yaml and .yml configuration files are supported "
+            "(got %s)" % file_extension
+        )
 
     if expand_env:
         environment = {}
@@ -165,6 +170,9 @@ def load_config(config, expand_env=False, env_file=None, force=False):
         with open(config, 'r') as file_handler:
             config = Template(file_handler.read())
             config = config.substitute(environment)
+    else:
+        config = open(config, 'r').read()
+
+    conf = yaml.load(config, Loader=yaml.SafeLoader)
 
-    conf.import_config(config)
-    return get_repos(conf.export('dict') or {}, force)
+    return get_repos(conf or {}, force)
diff --git a/setup.py b/setup.py
index be72d56..04b2be6 100644
--- a/setup.py
+++ b/setup.py
@@ -36,7 +36,7 @@
         'setuptools_scm',
     ],
     install_requires=[
-        'kaptan',
+        'PyYAML>=5',
         'argcomplete',
         'colorama',
         'requests',
diff --git a/tests/test_config.py b/tests/test_config.py
index a5e070f..0c9fa50 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -4,9 +4,10 @@
 import os
 import tempfile
 import unittest
-import kaptan
 from textwrap import dedent
 
+import yaml
+
 from git_aggregator import config
 from git_aggregator.exception import ConfigException
 from git_aggregator._compat import PY2
@@ -15,9 +16,7 @@
 class TestConfig(unittest.TestCase):
 
     def _parse_config(self, config_str):
-        conf = kaptan.Kaptan(handler='yaml')
-        conf.import_config(config_str)
-        return conf.export('dict')
+        return yaml.load(config_str, Loader=yaml.SafeLoader)
 
     def test_load(self):
         config_yaml = """