diff --git a/.changeset/komga-unset-site.md b/.changeset/komga-unset-site.md
new file mode 100644
index 0000000..f1fb92f
--- /dev/null
+++ b/.changeset/komga-unset-site.md
@@ -0,0 +1,5 @@
+---
+'@lnreader/plugin-runtime': patch
+---
+
+Accept self-hosted plugins (such as komga) whose `site` is undefined until their URL setting is configured.
diff --git a/packages/plugin-runtime/src/plugins/sandbox.ts b/packages/plugin-runtime/src/plugins/sandbox.ts
index 74e0598..e456b1e 100644
--- a/packages/plugin-runtime/src/plugins/sandbox.ts
+++ b/packages/plugin-runtime/src/plugins/sandbox.ts
@@ -46,11 +46,14 @@ export function assertPluginShape(
     throw new InvalidPluginError(id, 'module did not export a plugin instance');
   }
   const p = value as Record<string, unknown>;
+  // Self-hosted sources (e.g. komga) read `site` from a user setting, so it
+  // is empty or undefined until configured. Normalize it to '' so callers
+  // can treat it as a string; the runner reports NEEDS_CONFIG on use.
+  if (p.pluginSettings && (p.site === undefined || p.site === null)) {
+    p.site = '';
+  }
   for (const field of ['id', 'name', 'site', 'version'] as const) {
-    // Self-hosted sources (e.g. komga) read `site` from a user setting, so it
-    // may be empty until configured.
-    const optional =
-      field === 'site' && typeof p.site === 'string' && !!p.pluginSettings;
+    const optional = field === 'site' && !!p.pluginSettings;
     if (typeof p[field] !== 'string' || (!p[field] && !optional)) {
       throw new InvalidPluginError(id, `missing string field "${field}"`);
     }
diff --git a/packages/plugin-runtime/test/sandbox.test.ts b/packages/plugin-runtime/test/sandbox.test.ts
index 523b6be..3575d90 100644
--- a/packages/plugin-runtime/test/sandbox.test.ts
+++ b/packages/plugin-runtime/test/sandbox.test.ts
@@ -78,6 +78,30 @@ describe('sandbox', () => {
     );
   });
 
+  it('accepts an unset site on plugins with settings', async () => {
+    const d = await deps();
+    const methods = [
+      'popularNovels',
+      'parseNovel',
+      'parseChapter',
+      'searchNovels',
+    ]
+      .map(m => `${m}() {}`)
+      .join(', ');
+    const code = (site: string) =>
+      `exports.default = { id: 'k', name: 'K', version: '1', site: ${site}, ` +
+      `pluginSettings: { url: { value: '', label: 'URL' } }, ${methods} }`;
+    expect(loadPlugin(code('undefined'), 'k', d).site).toBe('');
+    expect(loadPlugin(code("''"), 'k', d).site).toBe('');
+    const noSettings = code('undefined').replace(
+      /pluginSettings: .*?\} \},/,
+      '',
+    );
+    expect(() => loadPlugin(noSettings, 'k', d)).toThrow(
+      'missing string field "site"',
+    );
+  });
+
   it('times out runaway top-level code', async () => {
     const d = { ...(await deps()), loadTimeoutMs: 50 };
     expect(() => loadPlugin('while (true) {}', 'spin', d)).toThrow(/timed out/);