diff --git a/pyaptly/cli.py b/pyaptly/cli.py
index ed48e6e..d61ea9e 100644
--- a/pyaptly/cli.py
+++ b/pyaptly/cli.py
@@ -7,6 +7,8 @@
 
 import click
 
+from .util import PyaptlyCliError
+
 lg = logging.getLogger(__name__)
 
 
@@ -26,7 +28,7 @@ def entry_point():
 
     try:
         cli.main(argv[1:])
-    except CalledProcessError:
+    except (CalledProcessError, PyaptlyCliError):
         pass  # already logged
     except Exception as e:
         if debug:
diff --git a/pyaptly/main.py b/pyaptly/main.py
index 8da90a0..ce3ada6 100755
--- a/pyaptly/main.py
+++ b/pyaptly/main.py
@@ -3,17 +3,9 @@
 import argparse
 import logging
 import sys
+from pathlib import Path
 
-import tomli
-
-from . import (
-    command,
-    custom_logger,
-    mirror,
-    publish,
-    repo,
-    snapshot,
-)
+from . import command, custom_logger, mirror, publish, repo, snapshot, util
 
 _logging_setup = False
 
@@ -45,8 +37,25 @@ def prepare(args):
     """Set pretend mode, read config and load state."""
     command.Command.pretend_mode = args.pretend
 
+    path = Path(args.config)
     with open(args.config, "rb") as f:
-        cfg = tomli.load(f)
+        if path.suffix == ".toml":
+            import tomli
+
+            cfg = tomli.load(f)
+        elif path.suffix == ".json":
+            import json
+
+            cfg = json.load(f)
+        elif path.suffix in (".yaml", ".yml"):
+            import yaml
+
+            cfg = yaml.safe_load(f)
+            lg.warn(
+                "NOTE: yaml has beed deprecated and will be remove on the next major release."
+            )
+        else:
+            util.exit_with_error(f"unknown config file extension: {path.suffix}")
     return cfg
 
 
diff --git a/pyaptly/tests/mirror.wuff b/pyaptly/tests/mirror.wuff
new file mode 100644
index 0000000..e69de29
diff --git a/pyaptly/tests/publish-publish.json b/pyaptly/tests/publish-publish.json
new file mode 100644
index 0000000..1d1b348
--- /dev/null
+++ b/pyaptly/tests/publish-publish.json
@@ -0,0 +1,78 @@
+{
+  "mirror": {
+    "fakerepo01": {
+      "max-tries": 2,
+      "archive": "http://localhost:3123/fakerepo01",
+      "gpg-keys": [
+        "2841988729C7F3FF"
+      ],
+      "components": "main",
+      "distribution": "main"
+    },
+    "fakerepo02": {
+      "archive": "http://localhost:3123/fakerepo02",
+      "gpg-keys": [
+        "2841988729C7F3FF"
+      ],
+      "components": "main",
+      "distribution": "main"
+    }
+  },
+  "snapshot": {
+    "fakerepo01-%T": {
+      "mirror": "fakerepo01",
+      "timestamp": {
+        "time": "00:00"
+      }
+    },
+    "fakerepo02-%T": {
+      "mirror": "fakerepo02",
+      "timestamp": {
+        "time": "00:00",
+        "repeat-weekly": "sat"
+      }
+    }
+  },
+  "publish": {
+    "fakerepo01": [
+      {
+        "gpg-key": "6D79A810B9B7ABAE",
+        "skip-contents": true,
+        "automatic-update": true,
+        "components": "main",
+        "distribution": "main",
+        "snapshots": [
+          {
+            "name": "fakerepo01-%T",
+            "timestamp": "current",
+            "archive-on-update": "archived-fakerepo01-%T"
+          }
+        ]
+      }
+    ],
+    "fakerepo02": [
+      {
+        "gpg-key": "6D79A810B9B7ABAE",
+        "automatic-update": true,
+        "components": "main",
+        "distribution": "main",
+        "snapshots": [
+          {
+            "name": "fakerepo02-%T",
+            "timestamp": "current",
+            "archive-on-update": "archived-fakerepo02-%T"
+          }
+        ]
+      }
+    ],
+    "fakerepo01-stable": [
+      {
+        "publish": "fakerepo01 main",
+        "gpg-key": "6D79A810B9B7ABAE",
+        "automatic-update": true,
+        "components": "main",
+        "distribution": "main"
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/pyaptly/tests/publish-publish.yaml b/pyaptly/tests/publish-publish.yaml
new file mode 100644
index 0000000..2b7c818
--- /dev/null
+++ b/pyaptly/tests/publish-publish.yaml
@@ -0,0 +1,50 @@
+mirror:
+  fakerepo01:
+    archive: http://localhost:3123/fakerepo01
+    components: main
+    distribution: main
+    gpg-keys:
+    - 2841988729C7F3FF
+    max-tries: 2
+  fakerepo02:
+    archive: http://localhost:3123/fakerepo02
+    components: main
+    distribution: main
+    gpg-keys:
+    - 2841988729C7F3FF
+publish:
+  fakerepo01:
+  - automatic-update: true
+    components: main
+    distribution: main
+    gpg-key: 6D79A810B9B7ABAE
+    skip-contents: true
+    snapshots:
+    - archive-on-update: archived-fakerepo01-%T
+      name: fakerepo01-%T
+      timestamp: current
+  fakerepo01-stable:
+  - automatic-update: true
+    components: main
+    distribution: main
+    gpg-key: 6D79A810B9B7ABAE
+    publish: fakerepo01 main
+  fakerepo02:
+  - automatic-update: true
+    components: main
+    distribution: main
+    gpg-key: 6D79A810B9B7ABAE
+    snapshots:
+    - archive-on-update: archived-fakerepo02-%T
+      name: fakerepo02-%T
+      timestamp: current
+snapshot:
+  fakerepo01-%T:
+    mirror: fakerepo01
+    timestamp:
+      time: 00:00
+  fakerepo02-%T:
+    mirror: fakerepo02
+    timestamp:
+      repeat-weekly: sat
+      time: 00:00
diff --git a/pyaptly/tests/test_mirror.py b/pyaptly/tests/test_mirror.py
index 12a0571..3be1629 100644
--- a/pyaptly/tests/test_mirror.py
+++ b/pyaptly/tests/test_mirror.py
@@ -4,7 +4,7 @@
 
 import pytest
 
-from .. import main, state_reader
+from .. import main, state_reader, util
 
 
 @pytest.mark.parametrize("config", ["debug.toml"], indirect=True)
@@ -46,6 +46,14 @@ def test_mirror_create(environment, config, caplog):
     assert state.mirrors() == {"fakerepo03"}
 
 
+@pytest.mark.parametrize("config", ["mirror.wuff"], indirect=True)
+def test_mirror_config_fail(config):
+    """Test if checking for unknown config file type works."""
+    args = ["-c", config, "mirror", "update", "asdfasdf"]
+    with pytest.raises(util.PyaptlyCliError):
+        main.main(args)
+
+
 @pytest.mark.parametrize("config", ["mirror-basic.toml"], indirect=True)
 def test_mirror_update(mirror_update):
     """Test if updating mirrors works."""
diff --git a/pyaptly/tests/test_publish.py b/pyaptly/tests/test_publish.py
index ad54926..d48c5c5 100644
--- a/pyaptly/tests/test_publish.py
+++ b/pyaptly/tests/test_publish.py
@@ -120,7 +120,11 @@ def test_publish_create_rotating(config, publish_create_rotating):
     pass
 
 
-@pytest.mark.parametrize("config", ["publish-publish.toml"], indirect=True)
+@pytest.mark.parametrize(
+    "config",
+    ["publish-publish.toml", "publish-publish.json", "publish-publish.yaml"],
+    indirect=True,
+)
 def test_publish_create_republish(config, publish_create_republish):
     """Test if creating republishes works."""
     pass
diff --git a/pyaptly/util.py b/pyaptly/util.py
index 344ee4c..05c0945 100644
--- a/pyaptly/util.py
+++ b/pyaptly/util.py
@@ -31,6 +31,15 @@
 lg = logging.getLogger(__name__)
 
 
+class PyaptlyCliError(Exception):
+    pass
+
+
+def exit_with_error(error):
+    lg.error(error)
+    raise PyaptlyCliError()
+
+
 def write_traceback():  # pragma: no cover
     with NamedTemporaryFile("w", delete=False) as tmp:
         tmp.write(traceback.format_exc())