diff --git a/src/run.ts b/src/run.ts
index 6b36639..846f104 100644
--- a/src/run.ts
+++ b/src/run.ts
@@ -152,7 +152,7 @@ async function renderPrompt(
     ANCHORS_PATH: anchorsPath,
   };
   const template = await Deno.readTextFile(
-    new URL("prompt.md", import.meta.url),
+    new URL("../prompt.md", import.meta.url),
   );
   return {
     prompt: template.replace(
diff --git a/src/workflow_test.ts b/src/workflow_test.ts
index 1e7dc58..28a4e51 100644
--- a/src/workflow_test.ts
+++ b/src/workflow_test.ts
@@ -106,6 +106,18 @@ Deno.test("the source protection script stages immutable action files", async ()
   }
 });
 
+Deno.test("module-relative runtime assets exist", async () => {
+  const module = new URL("run.ts", import.meta.url);
+  const source = await Deno.readTextFile(module);
+  for (
+    const match of source.matchAll(/new URL\("([^"]+)", import\.meta\.url\)/g)
+  ) {
+    const asset = new URL(match[1], module);
+    const stat = await Deno.stat(asset);
+    assert(stat.isFile, asset.pathname);
+  }
+});
+
 Deno.test("the repository uses its trusted main action", async () => {
   const workflow = await yaml(".gitea/workflows/agents.yml");
   const job = mapping(mapping(workflow.jobs, "jobs").agent, "jobs.agent");