diff --git a/markdown_it/tree.py b/markdown_it/tree.py
index 7e775204..5369157b 100644
--- a/markdown_it/tree.py
+++ b/markdown_it/tree.py
@@ -162,7 +162,7 @@ def type(self) -> str:
         if self.token:
             return self.token.type
         assert self.nester_tokens
-        return _removesuffix(self.nester_tokens.opening.type, "_open")
+        return self.nester_tokens.opening.type.removesuffix("_open")
 
     @property
     def next_sibling(self: _NodeType) -> _NodeType | None:
@@ -331,14 +331,3 @@ def hidden(self) -> bool:
         """If it's true, ignore this element when rendering.
         Used for tight lists to hide paragraphs."""
         return self._attribute_token().hidden
-
-
-def _removesuffix(string: str, suffix: str) -> str:
-    """Remove a suffix from a string.
-
-    Replace this with str.removesuffix() from stdlib when minimum Python
-    version is 3.9.
-    """
-    if suffix and string.endswith(suffix):
-        return string[: -len(suffix)]
-    return string