diff --git a/vdirsyncer/cli/config.py b/vdirsyncer/cli/config.py
index c863f32..344ce80 100644
--- a/vdirsyncer/cli/config.py
+++ b/vdirsyncer/cli/config.py
@@ -107,10 +107,7 @@ class _ConfigReader:
         self._storages: dict[str, dict[str, str]] = {}
 
     def _parse_section(
-        self,
-        section_type: str,
-        name: str,
-        options: dict[str, Any]
+        self, section_type: str, name: str, options: dict[str, Any]
     ) -> None:
         validate_section_name(name, section_type)
         if name in self._seen_names:
@@ -129,7 +126,7 @@ class _ConfigReader:
             raise ValueError("Unknown section type.")
 
     def parse(
-        self
+        self,
     ) -> tuple[dict[str, str], dict[str, dict[str, str]], dict[str, dict[str, str]]]:
         for section in self._parser.sections():
             if " " in section:
@@ -157,8 +154,7 @@ class _ConfigReader:
 
 
 def _parse_options(
-    items: list[tuple[str, str]],
-    section: str | None = None
+    items: list[tuple[str, str]], section: str | None = None
 ) -> Generator[tuple[str, dict[str, str]], None, None]:
     for key, value in items:
         try:
@@ -172,7 +168,7 @@ class Config:
         self,
         general: dict[str, str],
         pairs: dict[str, dict[str, str]],
-        storages: dict[str, dict[str, str]]
+        storages: dict[str, dict[str, str]],
     ) -> None:
         self.general = general
         self.storages = storages
@@ -258,8 +254,7 @@ class PairConfig:
             raise ValueError("Unknown options: {}".format(", ".join(options)))
 
     def _process_conflict_resolution_param(
-        self,
-        conflict_resolution: str | list[str] | None
+        self, conflict_resolution: str | list[str] | None
     ):
         if conflict_resolution in (None, "a wins", "b wins"):
             return conflict_resolution
@@ -337,12 +332,7 @@ load_config = Config.from_filename_or_environment
 
 
 def _resolve_conflict_via_command(
-    a,
-    b,
-    command,
-    a_name,
-    b_name,
-    _check_call=None
+    a, b, command, a_name, b_name, _check_call=None
 ) -> Item:
     import shutil
     import tempfile