diff --git a/lib/spack/docs/conf.py b/lib/spack/docs/conf.py
index 87e6f6b227b..cb10f2d2822 100644
--- a/lib/spack/docs/conf.py
+++ b/lib/spack/docs/conf.py
@@ -206,6 +206,7 @@ def setup(sphinx):
     ("py:class", "TextIO"),
     ("py:class", "hashlib._Hash"),
     ("py:class", "concurrent.futures._base.Executor"),
+    ("py:class", "jsonschema.exceptions.ValidationError"),
     # Spack classes that are private and we don't want to expose
     ("py:class", "spack.provider_index._IndexBase"),
     ("py:class", "spack.repo._PrependFileLoader"),