diff --git a/aiogram/utils/text_decorations.py b/aiogram/utils/text_decorations.py
index 77dc0ff3..3d22f637 100644
--- a/aiogram/utils/text_decorations.py
+++ b/aiogram/utils/text_decorations.py
@@ -163,7 +163,7 @@ class HtmlDecoration(TextDecoration):
 
 
 class MarkdownDecoration(TextDecoration):
-    MARKDOWN_QUOTE_PATTERN: Pattern[str] = re.compile(r"([_*\[\]()~`>#+\-|{}.!])")
+    MARKDOWN_QUOTE_PATTERN: Pattern[str] = re.compile(r"([_*\[\]()~`>#+\-=|{}.!\\])")
 
     def link(self, value: str, link: str) -> str:
         return f"[{value}]({link})"
diff --git a/tests/test_utils/test_markdown.py b/tests/test_utils/test_markdown.py
new file mode 100644
index 00000000..02faea2a
--- /dev/null
+++ b/tests/test_utils/test_markdown.py
@@ -0,0 +1,11 @@
+import pytest
+
+from aiogram.utils import markdown
+
+
+class TestMarkdownEscape:
+  def test_equality_sign_is_escaped(self):
+    assert markdown.escape_md(r"e = mc2") == r"e \= mc2"
+
+  def test_pre_escaped(self):
+    assert markdown.escape_md(r"hello\.") == r"hello\\\."