diff --git a/dashboard/optional_deps.py b/dashboard/optional_deps.py
index de0e7cb05..cd792190d 100644
--- a/dashboard/optional_deps.py
+++ b/dashboard/optional_deps.py
@@ -1,3 +1,8 @@
+# These imports determine whether or not a user has the required dependencies
+# to launch the optional dashboard API server.
+# If any of these imports fail, the dashboard API server will not be launched.
+# Please add important dashboard-api dependencies to this list.
+
 # These checks have to come first because aiohttp looks
 # for opencensus, too, and raises a different error otherwise.
 import opencensus  # noqa: F401
@@ -10,3 +15,4 @@ import aiohttp_cors  # noqa: F401
 from aiohttp import hdrs  # noqa: F401
 from aiohttp.typedefs import PathLike  # noqa: F401
 from aiohttp.web import RouteDef  # noqa: F401
+import pydantic  # noqa: F401
diff --git a/python/setup.py b/python/setup.py
index d08ad9c7f..5df11e4d6 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -211,6 +211,8 @@ if setup_spec.type == SetupType.RAY:
             "fsspec",
         ],
         "default": [
+            # If adding dependencies necessary to launch the dashboard api server,
+            # please add it to dashboard/optional_deps.py as well.
             "aiohttp >= 3.7",
             "aiohttp_cors",
             "colorful",