diff --git a/datasette/app.py b/datasette/app.py
index af89d7f6..dfba438a 100644
--- a/datasette/app.py
+++ b/datasette/app.py
@@ -600,8 +600,8 @@ class Datasette:
         add_route(
             asgi_static(app_root / "datasette" / "static"), r"/-/static/(?P<path>.*)$"
         )
-        # for path, dirname in self.static_mounts:
-        #     app.static(path, dirname)
+        for path, dirname in self.static_mounts:
+            add_route(asgi_static(dirname), r"/" + path + "/(?P<path>.*)$")
 
         # Mount any plugin static/ directories
         for plugin in get_plugins(pm):
diff --git a/tests/fixtures.py b/tests/fixtures.py
index b1f54185..e98bf492 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -82,6 +82,7 @@ def make_app_client(
     is_immutable=False,
     extra_databases=None,
     inspect_data=None,
+    static_mounts=None,
 ):
     with tempfile.TemporaryDirectory() as tmpdir:
         filepath = os.path.join(tmpdir, filename)
@@ -123,6 +124,7 @@ def make_app_client(
             plugins_dir=plugins_dir,
             config=config,
             inspect_data=inspect_data,
+            static_mounts=static_mounts,
         )
         ds.sqlite_functions.append(("sleep", 1, lambda n: time.sleep(float(n))))
         client = TestClient(ds.app())
diff --git a/tests/test_html.py b/tests/test_html.py
index f9ff393f..60014691 100644
--- a/tests/test_html.py
+++ b/tests/test_html.py
@@ -8,6 +8,7 @@ from .fixtures import (  # noqa
     METADATA,
 )
 import json
+import pathlib
 import pytest
 import re
 import urllib.parse
@@ -52,6 +53,16 @@ def test_static(app_client):
     assert "text/css" == response.headers["content-type"]
 
 
+def test_static_mounts():
+    for client in make_app_client(
+        static_mounts=[("custom-static", str(pathlib.Path(__file__).parent))]
+    ):
+        response = client.get("/custom-static/test_html.py")
+        assert response.status == 200
+        response = client.get("/custom-static/not_exists.py")
+        assert response.status == 404
+
+
 def test_memory_database_page():
     for client in make_app_client(memory=True):
         response = client.get("/:memory:")