diff --git a/doc/conf.py b/doc/conf.py
index 1de49fc2721..40c64bd0e74 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -63,7 +63,7 @@
     "sphinx_design",
     "sphinx_inline_tabs",
     "sphinx_remove_toctrees",
-    "sphinx_llms_txt",
+    "sphinx_llm.txt",
 ]
 
 
@@ -178,6 +178,11 @@
 # mermaid config
 mermaid_version = "11.6.0"
 
+# sphinx-llm config
+# Some jupyter-execute cells are not thread-safe, so we need to build sequentially.
+# See https://github.com/pydata/xarray/pull/11003#issuecomment-3641648868
+llms_txt_build_parallel = False
+
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ["_templates", sphinx_autosummary_accessors.templates_path]
 
diff --git a/pixi.toml b/pixi.toml
index f7f80674d22..5617448b610 100644
--- a/pixi.toml
+++ b/pixi.toml
@@ -231,7 +231,7 @@ sphinx-autosummary-accessors = "*"
 sphinx-copybutton = "*"
 sphinx-design = "*"
 sphinx-inline-tabs = "*"
-sphinx-llms-txt = "*"
+sphinx-llm = ">=0.2.1"
 sphinx = ">=6,<8"
 sphinxcontrib-mermaid = "*"
 sphinxcontrib-srclinks = "*"