diff --git a/doc/install.rst b/doc/install.rst
index 90d2e22b1..cfdb246e7 100644
--- a/doc/install.rst
+++ b/doc/install.rst
@@ -26,6 +26,7 @@ Optional:
 * ``pandas`` (>=1.3.2, for generating event statistics)
 * ``EDFlib-Python`` (>=1.0.6, for writing EDF data with ``mne`` versions <1.7)
 * ``edfio`` (>=0.2.1, for writing EDF data)
+* ``defusedxml`` (for writing reading EGI MFF data and BrainVision montages)
 
 We recommend installing ``mne-bids`` into an isolated Python environment,
 for example created via ``conda``
diff --git a/pyproject.toml b/pyproject.toml
index 556709160..ab83b99f8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -74,7 +74,7 @@ doc = [
     "pandas",
     "mne-nirs @ https://github.com/mne-tools/mne-nirs/archive/refs/heads/main.zip",
     "seaborn",
-    "openneuro-py"
+    "openneuro-py",
 ]
 
 # Dependencies for developer installations