diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7b4839fd..0ea7668c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,14 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 <!-- insertion marker -->
+## [0.21.2](https://github.com/mkdocstrings/mkdocstrings/releases/tag/0.21.2) - 2023-04-06
+
+<small>[Compare with 0.21.1](https://github.com/mkdocstrings/mkdocstrings/compare/0.21.1...0.21.2)</small>
+
+### Bug Fixes
+
+- Fix regression with LRU cached method ([85efbd2](https://github.com/mkdocstrings/mkdocstrings/commit/85efbd285d4c8977755bda1c36220b241a9e1502) by Timothée Mazzucotelli). [Issue #549](https://github.com/mkdocstrings/mkdocstrings/issues/549)
+
 ## [0.21.1](https://github.com/mkdocstrings/mkdocstrings/releases/tag/0.21.1) - 2023-04-05
 
 <small>[Compare with 0.21.0](https://github.com/mkdocstrings/mkdocstrings/compare/0.21.0...0.21.1)</small>
diff --git a/src/mkdocstrings/plugin.py b/src/mkdocstrings/plugin.py
index a35309c8..5233cf4f 100644
--- a/src/mkdocstrings/plugin.py
+++ b/src/mkdocstrings/plugin.py
@@ -231,7 +231,7 @@ def on_config(self, config: Config, **kwargs: Any) -> Config:  # noqa: ARG002
             inv_loader = futures.ThreadPoolExecutor(4)
             for handler_name, import_item in to_import:
                 future = inv_loader.submit(
-                    self._load_inventory,
+                    self._load_inventory,  # type: ignore[misc]
                     self.get_handler(handler_name).load_inventory,
                     **import_item,
                 )
@@ -330,9 +330,9 @@ def get_handler(self, handler_name: str) -> BaseHandler:
         return self.handlers.get_handler(handler_name)
 
     @classmethod
-    @functools.lru_cache(maxsize=None)
     # lru_cache does not allow mutable arguments such lists, but that is what we load from YAML config.
     @list_to_tuple
+    @functools.lru_cache(maxsize=None)
     def _load_inventory(cls, loader: InventoryLoaderType, url: str, **kwargs: Any) -> Mapping[str, str]:
         """Download and process inventory files using a handler.
 
diff --git a/tests/test_inventory.py b/tests/test_inventory.py
index ecbb3cd2..ce707296 100644
--- a/tests/test_inventory.py
+++ b/tests/test_inventory.py
@@ -5,6 +5,7 @@
 import sys
 from io import BytesIO
 from os.path import join
+from typing import TYPE_CHECKING
 
 import pytest
 from mkdocs.commands.build import build
@@ -12,6 +13,8 @@
 
 from mkdocstrings.inventory import Inventory, InventoryItem
 
+if TYPE_CHECKING:
+    from mkdocstrings.plugin import MkdocstringsPlugin
 sphinx = pytest.importorskip("sphinx.util.inventory", reason="Sphinx is not installed")
 
 
@@ -55,3 +58,12 @@ def test_sphinx_load_mkdocstrings_inventory_file() -> None:
 
     for item in own_inv.values():
         assert item.name in sphinx_inv[f"{item.domain}:{item.role}"]
+
+
+def test_load_inventory(plugin: MkdocstringsPlugin) -> None:
+    """Test the plugin inventory loading method.
+
+    Parameters:
+        plugin: A mkdocstrings plugin instance.
+    """
+    plugin._load_inventory(loader=lambda *args, **kwargs: (), url="https://example.com", domains=["a", "b"])  # type: ignore[misc,arg-type]