diff --git a/api/advent22_api/core/webdav.py b/api/advent22_api/core/webdav.py
index 5904c74..979554a 100644
--- a/api/advent22_api/core/webdav.py
+++ b/api/advent22_api/core/webdav.py
@@ -1,3 +1,4 @@
+import asyncio
 import re
 from io import BytesIO
 
@@ -29,7 +30,12 @@ class WebDAV:
         Liste aller Dateien im Ordner `directory`, die zur RegEx `regex` passen
         """
 
-        ls = cls._webdav_client.list(directory)
+        loop = asyncio.get_running_loop()
+        ls = await loop.run_in_executor(
+            None,
+            cls._webdav_client.list,
+            directory,
+        )
 
         return [f"{directory}/{path}" for path in ls if regex.search(path)]
 
@@ -40,7 +46,12 @@ class WebDAV:
         `True`, wenn an Pfad `path` eine Datei existiert
         """
 
-        return cls._webdav_client.check(path)
+        loop = asyncio.get_running_loop()
+        return await loop.run_in_executor(
+            None,
+            cls._webdav_client.check,
+            path,
+        )
 
     @classmethod
     @(_rb_ttl := AsyncTTL(time_to_live=SETTINGS.webdav.cache_ttl, skip_args=1))
@@ -50,7 +61,12 @@ class WebDAV:
         """
 
         buffer = BytesIO()
-        cls._webdav_client.resource(path).write_to(buffer)
+        loop = asyncio.get_running_loop()
+        await loop.run_in_executor(
+            None,
+            cls._webdav_client.resource(path).write_to,
+            buffer,
+        )
         buffer.seek(0)
 
         return buffer.read()
@@ -69,7 +85,12 @@ class WebDAV:
         Bytes `buffer` in Datei in Pfad `path` schreiben
         """
 
-        cls._webdav_client.resource(path).read_from(buffer)
+        loop = asyncio.get_running_loop()
+        await loop.run_in_executor(
+            None,
+            cls._webdav_client.resource(path).read_from,
+            buffer,
+        )
 
         try:
             # hack: zugehörigen Cache-Eintrag entfernen