diff --git a/telethon/tl/tlobject.py b/telethon/tl/tlobject.py
index 2ba6ef14..68c5e741 100644
--- a/telethon/tl/tlobject.py
+++ b/telethon/tl/tlobject.py
@@ -36,7 +36,9 @@ class TLObject:
                     ', '.join(TLObject.pretty_format(x) for x in obj)
                 )
             elif isinstance(obj, datetime):
-                return 'datetime.utcfromtimestamp({})'.format(obj.timestamp())
+                return 'datetime.utcfromtimestamp({})'.format(
+                    int(obj.timestamp())
+                )
             else:
                 return repr(obj)
         else:
@@ -82,7 +84,7 @@ class TLObject:
 
             elif isinstance(obj, datetime):
                 result.append('datetime.utcfromtimestamp(')
-                result.append(repr(obj.timestamp()))
+                result.append(repr(int(obj.timestamp())))
                 result.append(')')
 
             else: