diff --git a/CHANGELOG.md b/CHANGELOG.md
index b01d34c..ea4f1cf 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 -->
+## [1.16.12](https://github.com/mkdocstrings/python/releases/tag/1.16.12) - 2025-06-03
+
+<small>[Compare with 1.16.11](https://github.com/mkdocstrings/python/compare/1.16.11...1.16.12)</small>
+
+### Bug Fixes
+
+- Only replace CSS class in first *highlighting* span ([d57740f](https://github.com/mkdocstrings/python/commit/d57740f874f056fb3ba1c6013ad04227df0f0af8) by Timothée Mazzucotelli). [Issue-281](https://github.com/mkdocstrings/python/issues/281)
+
 ## [1.16.11](https://github.com/mkdocstrings/python/releases/tag/1.16.11) - 2025-05-24
 
 <small>[Compare with 1.16.10](https://github.com/mkdocstrings/python/compare/1.16.10...1.16.11)</small>
diff --git a/src/mkdocstrings_handlers/python/_internal/handler.py b/src/mkdocstrings_handlers/python/_internal/handler.py
index 896a70e..158d7dd 100644
--- a/src/mkdocstrings_handlers/python/_internal/handler.py
+++ b/src/mkdocstrings_handlers/python/_internal/handler.py
@@ -360,7 +360,7 @@ def get_aliases(self, identifier: str) -> tuple[str, ...]:
             return tuple(f"{alias}({parameter})" for alias in aliases)
         return tuple(aliases)
 
-    def normalize_extension_paths(self, extensions: Sequence) -> Sequence:
+    def normalize_extension_paths(self, extensions: Sequence) -> list[str | dict[str, Any]]:
         """Resolve extension paths relative to config file.
 
         Parameters:
@@ -369,7 +369,7 @@ def normalize_extension_paths(self, extensions: Sequence) -> Sequence:
         Returns:
             The normalized extensions.
         """
-        normalized = []
+        normalized: list[str | dict[str, Any]] = []
 
         for ext in extensions:
             if isinstance(ext, dict):
diff --git a/src/mkdocstrings_handlers/python/_internal/rendering.py b/src/mkdocstrings_handlers/python/_internal/rendering.py
index 902d794..897b657 100644
--- a/src/mkdocstrings_handlers/python/_internal/rendering.py
+++ b/src/mkdocstrings_handlers/python/_internal/rendering.py
@@ -190,7 +190,7 @@ def do_format_signature(
     # To fix this, we replace the CSS class in the first span with `nf`,
     # unless we already found an `nf` span.
     if not re.search(r'<span class="nf">', signature):
-        signature = re.sub(r'<span class="[a-z]+">', '<span class="nf">', signature, count=1)
+        signature = re.sub(r'<span class="[a-z]{1,2}">', '<span class="nf">', signature, count=1)
 
     if stash := env.filters["stash_crossref"].stash:
         for key, value in stash.items():