diff --git a/rst_to_myst/data/directives.yml b/rst_to_myst/data/directives.yml
index 7e3ba2b..3c3ca08 100644
--- a/rst_to_myst/data/directives.yml
+++ b/rst_to_myst/data/directives.yml
@@ -17,6 +17,19 @@ docutils.parsers.rst.directives.admonitions.Note: parse_content
 docutils.parsers.rst.directives.admonitions.Tip: parse_content
 docutils.parsers.rst.directives.admonitions.Warning: parse_content
 
+# admonitions (sphinx 8.2+ overrides the docutils classes)
+sphinx.directives.admonitions.Admonition: parse_all
+sphinx.directives.admonitions.Attention: parse_content
+sphinx.directives.admonitions.Caution: parse_content
+sphinx.directives.admonitions.Danger: parse_content
+sphinx.directives.admonitions.Error: parse_content
+sphinx.directives.admonitions.Hint: parse_content
+sphinx.directives.admonitions.Important: parse_content
+sphinx.directives.admonitions.Note: parse_content
+sphinx.directives.admonitions.Tip: parse_content
+sphinx.directives.admonitions.Warning: parse_content
+sphinx.directives.admonitions.SeeAlso: parse_content
+
 # docutils other (see https://docutils.sourceforge.io/docs/ref/rst/directives.html#figure)
 docutils.parsers.rst.directives.body.CodeBlock: direct
 docutils.parsers.rst.directives.body.Compound: eval_rst
diff --git a/tests/test_admonitions.py b/tests/test_admonitions.py
new file mode 100644
index 0000000..5b0abca
--- /dev/null
+++ b/tests/test_admonitions.py
@@ -0,0 +1,43 @@
+"""Sphinx 8.2+ replaces docutils admonition classes; they must still convert."""
+
+from docutils import nodes
+from docutils.parsers.rst.directives.admonitions import BaseAdmonition
+
+from rst_to_myst.markdownit import MarkdownItRenderer
+from rst_to_myst.mdformat_render import from_tokens
+from rst_to_myst.namespace import compile_namespace
+from rst_to_myst.parser import to_docutils_ast
+
+
+class Warning(BaseAdmonition):
+    """Stand-in for ``sphinx.directives.admonitions.Warning``."""
+
+    node_class = nodes.warning
+
+
+Warning.__module__ = "sphinx.directives.admonitions"
+
+
+def _convert(text: str) -> str:
+    namespace = compile_namespace(use_sphinx=False)
+    namespace.directives["warning"] = Warning
+    document, warning_stream = to_docutils_ast(
+        text, use_sphinx=False, namespace=namespace
+    )
+    assert warning_stream.getvalue() == ""
+    tokens = MarkdownItRenderer(
+        document,
+        warning_stream=warning_stream,
+        colon_fences=True,
+        dollar_math=True,
+    ).to_tokens()
+    return from_tokens(tokens, warning_stream=warning_stream)
+
+
+def test_sphinx_overridden_warning_is_not_eval_rst():
+    # Issue #97: ``.. warning:: This is a warning`` became an eval-rst fence
+    # after Sphinx started registering its own admonition classes.
+    text = _convert(".. warning:: This is a warning\n")
+    assert "{eval-rst}" not in text
+    assert "This is a warning" in text
+    assert "{warning}" in text