diff --git a/pyrogram/client/style/html.py b/pyrogram/client/style/html.py
index 63a80733..4cafeb35 100644
--- a/pyrogram/client/style/html.py
+++ b/pyrogram/client/style/html.py
@@ -34,8 +34,8 @@ class HTML:
     HTML_RE = re.compile(r"<(\w+)(?: href=([\"'])([^<]+)\2)?>([^>]+)</\1>")
     MENTION_RE = re.compile(r"tg://user\?id=(\d+)")
 
-    def __init__(self, peers_by_id):
-        self.peers_by_id = peers_by_id
+    def __init__(self, peers_by_id: dict = None):
+        self.peers_by_id = peers_by_id or {}
 
     def parse(self, text):
         entities = []
diff --git a/pyrogram/client/style/markdown.py b/pyrogram/client/style/markdown.py
index 7a67d0ae..61b60e17 100644
--- a/pyrogram/client/style/markdown.py
+++ b/pyrogram/client/style/markdown.py
@@ -51,8 +51,8 @@ class Markdown:
     ))
     MENTION_RE = re.compile(r"tg://user\?id=(\d+)")
 
-    def __init__(self, peers_by_id: dict):
-        self.peers_by_id = peers_by_id
+    def __init__(self, peers_by_id: dict = None):
+        self.peers_by_id = peers_by_id or {}
 
     def parse(self, message: str):
         message = utils.add_surrogates(message).strip()