diff --git a/CHANGES/1176.bugfix.rst b/CHANGES/1176.bugfix.rst
new file mode 100644
index 00000000..57f67202
--- /dev/null
+++ b/CHANGES/1176.bugfix.rst
@@ -0,0 +1 @@
+Fixed the markdown spoiler parser.
diff --git a/aiogram/utils/text_decorations.py b/aiogram/utils/text_decorations.py
index 70f96388..97430a32 100644
--- a/aiogram/utils/text_decorations.py
+++ b/aiogram/utils/text_decorations.py
@@ -233,7 +233,7 @@ class MarkdownDecoration(TextDecoration):
         return f"~{value}~"
 
     def spoiler(self, value: str) -> str:
-        return f"|{value}|"
+        return f"||{value}||"
 
     def quote(self, value: str) -> str:
         return re.sub(pattern=self.MARKDOWN_QUOTE_PATTERN, repl=r"\\\1", string=value)
diff --git a/tests/test_utils/test_text_decorations.py b/tests/test_utils/test_text_decorations.py
index 01fbabb6..056bd1cb 100644
--- a/tests/test_utils/test_text_decorations.py
+++ b/tests/test_utils/test_text_decorations.py
@@ -90,7 +90,7 @@ class TestTextDecoration:
             [markdown_decoration, MessageEntity(type="bot_command", offset=0, length=5), "test"],
             [markdown_decoration, MessageEntity(type="email", offset=0, length=5), "test"],
             [markdown_decoration, MessageEntity(type="phone_number", offset=0, length=5), "test"],
-            [markdown_decoration, MessageEntity(type="spoiler", offset=0, length=5), "|test|"],
+            [markdown_decoration, MessageEntity(type="spoiler", offset=0, length=5), "||test||"],
             [
                 markdown_decoration,
                 MessageEntity(type="custom_emoji", offset=0, length=5, custom_emoji_id="42"),