diff --git a/src/server/piWebPluginService.test.ts b/src/server/piWebPluginService.test.ts
index 7507aa7..6b00d34 100644
--- a/src/server/piWebPluginService.test.ts
+++ b/src/server/piWebPluginService.test.ts
@@ -44,6 +44,22 @@ describe("PiWebPluginService", () => {
     expect(asset?.content.toString("utf8")).toContain("export default");
   });
 
+  it("preserves content types for extension-only asset names", async () => {
+    const pluginDir = join(tempDir, "plugins", "extension-only");
+    await writePlugin(pluginDir, {
+      packageJson: { piWeb: { plugins: [{ id: "extension-only", module: ".js" }] } },
+      files: {
+        ".js": "export default {};",
+        ".svg": '<svg xmlns="http://www.w3.org/2000/svg"></svg>',
+      },
+    });
+
+    const service = new PiWebPluginService({ roots: [{ path: join(tempDir, "plugins"), source: "test", scope: "local" }], packageProvider: false });
+
+    await expect(service.readAsset("extension-only", ".js")).resolves.toMatchObject({ contentType: "application/javascript; charset=utf-8" });
+    await expect(service.readAsset("extension-only", ".svg")).resolves.toMatchObject({ contentType: "image/svg+xml" });
+  });
+
   it("serves nested SVG assets with a browser-compatible content type", async () => {
     const pluginDir = join(tempDir, "plugins", "icons");
     const svg = '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"></svg>';
diff --git a/src/server/piWebPluginService.ts b/src/server/piWebPluginService.ts
index 0566153..45938ea 100644
--- a/src/server/piWebPluginService.ts
+++ b/src/server/piWebPluginService.ts
@@ -1,6 +1,6 @@
 import { existsSync } from "node:fs";
 import { readdir, readFile, realpath, stat } from "node:fs/promises";
-import { dirname, extname, join, relative, resolve, sep } from "node:path";
+import { dirname, join, relative, resolve, sep } from "node:path";
 import { fileURLToPath } from "node:url";
 import { DefaultPackageManager, getAgentDir, SettingsManager } from "@earendil-works/pi-coding-agent";
 import { loadPiWebConfig, piWebDataDir, type PiWebConfig } from "../config.js";
@@ -335,14 +335,13 @@ function isWithin(root: string, candidate: string): boolean {
 }
 
 function contentTypeFor(path: string): string {
-  switch (extname(path).toLowerCase()) {
-    case ".js": return "application/javascript; charset=utf-8";
-    case ".json": return "application/json; charset=utf-8";
-    case ".css": return "text/css; charset=utf-8";
-    case ".html": return "text/html; charset=utf-8";
-    case ".svg": return "image/svg+xml";
-    default: return "application/octet-stream";
-  }
+  const lowerPath = path.toLowerCase();
+  if (lowerPath.endsWith(".js")) return "application/javascript; charset=utf-8";
+  if (lowerPath.endsWith(".json")) return "application/json; charset=utf-8";
+  if (lowerPath.endsWith(".css")) return "text/css; charset=utf-8";
+  if (lowerPath.endsWith(".html")) return "text/html; charset=utf-8";
+  if (lowerPath.endsWith(".svg")) return "image/svg+xml";
+  return "application/octet-stream";
 }
 
 function isRecord(value: unknown): value is Record<string, unknown> {