diff --git a/vdirsyncer/cli/tasks.py b/vdirsyncer/cli/tasks.py
index 83014f6..7a94f9f 100644
--- a/vdirsyncer/cli/tasks.py
+++ b/vdirsyncer/cli/tasks.py
@@ -121,9 +121,7 @@ async def repair_collection(
                 break
         else:
             raise exceptions.UserError(
-                "Couldn't find collection {} for storage {}.".format(
-                    collection, storage_name
-                )
+                f"Couldn't find collection {collection} for storage {storage_name}."
             )
 
     config["type"] = storage_type
diff --git a/vdirsyncer/cli/utils.py b/vdirsyncer/cli/utils.py
index 0f48a2e..9cf487f 100644
--- a/vdirsyncer/cli/utils.py
+++ b/vdirsyncer/cli/utils.py
@@ -323,9 +323,7 @@ def assert_permissions(path, wanted):
     permissions = os.stat(path).st_mode & 0o777
     if permissions > wanted:
         cli_logger.warning(
-            "Correcting permissions of {} from {:o} to {:o}".format(
-                path, permissions, wanted
-            )
+            f"Correcting permissions of {path} from {permissions:o} to {wanted:o}"
         )
         os.chmod(path, wanted)
 
diff --git a/vdirsyncer/storage/dav.py b/vdirsyncer/storage/dav.py
index dcaf15e..e21e0aa 100644
--- a/vdirsyncer/storage/dav.py
+++ b/vdirsyncer/storage/dav.py
@@ -198,9 +198,7 @@ class Discover:
             # E.g. Synology NAS
             # See https://github.com/pimutils/vdirsyncer/issues/498
             dav_logger.debug(
-                "No current-user-principal returned, re-using URL {}".format(
-                    response.url
-                )
+                f"No current-user-principal returned, re-using URL {response.url}"
             )
             return response.url.human_repr()
         return urlparse.urljoin(str(response.url), rv.text).rstrip("/") + "/"
@@ -649,9 +647,7 @@ class DAVStorage(Storage):
             contenttype = getattr(props.find("{DAV:}getcontenttype"), "text", None)
             if not self._is_item_mimetype(contenttype):
                 dav_logger.debug(
-                    "Skipping {!r}, {!r} != {!r}.".format(
-                        href, contenttype, self.item_mimetype
-                    )
+                    f"Skipping {href!r}, {contenttype!r} != {self.item_mimetype!r}."
                 )
                 continue
 
@@ -831,9 +827,7 @@ class CalDAVStorage(DAVStorage):
                 start = start.strftime(CALDAV_DT_FORMAT)
                 end = end.strftime(CALDAV_DT_FORMAT)
 
-                timefilter = '<C:time-range start="{start}" end="{end}"/>'.format(
-                    start=start, end=end
-                )
+                timefilter = f'<C:time-range start="{start}" end="{end}"/>'
             else:
                 timefilter = ""
 
diff --git a/vdirsyncer/sync/__init__.py b/vdirsyncer/sync/__init__.py
index 330a220..d596488 100644
--- a/vdirsyncer/sync/__init__.py
+++ b/vdirsyncer/sync/__init__.py
@@ -205,9 +205,7 @@ class Upload(Action):
             href = etag = None
         else:
             sync_logger.info(
-                "Copying (uploading) item {} to {}".format(
-                    self.ident, self.dest.storage
-                )
+                f"Copying (uploading) item {self.ident} to {self.dest.storage}"
             )
             href, etag = await self.dest.storage.upload(self.item)
             assert href is not None