diff --git a/telethon/crypto/cdn_decrypter.py b/telethon/crypto/cdn_decrypter.py
index f4b0ef3e..0381f62d 100644
--- a/telethon/crypto/cdn_decrypter.py
+++ b/telethon/crypto/cdn_decrypter.py
@@ -19,7 +19,7 @@ class CdnDecrypter:
         self.cdn_file_hashes = cdn_file_hashes
 
     @staticmethod
-    def prepare_decrypter(client, cdn_client, cdn_redirect):
+    async def prepare_decrypter(client, cdn_client, cdn_redirect):
         """Prepares a CDN decrypter, returning (decrypter, file data).
            'client' should be an existing client not connected to a CDN.
            'cdn_client' should be an already-connected TelegramBareClient
@@ -38,14 +38,14 @@ class CdnDecrypter:
             cdn_aes, cdn_redirect.cdn_file_hashes
         )
 
-        cdn_file = cdn_client(GetCdnFileRequest(
+        cdn_file = await cdn_client(GetCdnFileRequest(
             file_token=cdn_redirect.file_token,
             offset=cdn_redirect.cdn_file_hashes[0].offset,
             limit=cdn_redirect.cdn_file_hashes[0].limit
         ))
         if isinstance(cdn_file, CdnFileReuploadNeeded):
             # We need to use the original client here
-            client(ReuploadCdnFileRequest(
+            await client(ReuploadCdnFileRequest(
                 file_token=cdn_redirect.file_token,
                 request_token=cdn_file.request_token
             ))
@@ -59,13 +59,13 @@ class CdnDecrypter:
 
         return decrypter, cdn_file
 
-    def get_file(self):
+    async def get_file(self):
         """Calls GetCdnFileRequest and decrypts its bytes.
            Also ensures that the file hasn't been tampered.
         """
         if self.cdn_file_hashes:
             cdn_hash = self.cdn_file_hashes.pop(0)
-            cdn_file = self.client(GetCdnFileRequest(
+            cdn_file = await self.client(GetCdnFileRequest(
                 self.file_token, cdn_hash.offset, cdn_hash.limit
             ))
             cdn_file.bytes = self.cdn_aes.encrypt(cdn_file.bytes)
diff --git a/telethon/telegram_bare_client.py b/telethon/telegram_bare_client.py
index 1728d98d..6e23b1fa 100644
--- a/telethon/telegram_bare_client.py
+++ b/telethon/telegram_bare_client.py
@@ -615,7 +615,7 @@ class TelegramBareClient:
 
                 try:
                     if cdn_decrypter:
-                        result = cdn_decrypter.get_file()
+                        result = await cdn_decrypter.get_file()
                     else:
                         result = await client(GetFileRequest(
                             input_location, offset, part_size
@@ -623,7 +623,7 @@ class TelegramBareClient:
 
                         if isinstance(result, FileCdnRedirect):
                             cdn_decrypter, result = \
-                                CdnDecrypter.prepare_decrypter(
+                                await CdnDecrypter.prepare_decrypter(
                                     client,
                                     await self._get_cdn_client(result),
                                     result