diff --git a/server/src/services/native-runtime/native-session-executor.test.ts b/server/src/services/native-runtime/native-session-executor.test.ts
index 90b849c2ee4..62712c6a608 100644
--- a/server/src/services/native-runtime/native-session-executor.test.ts
+++ b/server/src/services/native-runtime/native-session-executor.test.ts
@@ -40,7 +40,6 @@ import {
   NativeSessionCleanupQuarantinedError,
   NativeProviderTerminalFailure,
   NativeSessionProtocolIntegrityError,
-  defaultCapabilityRunnerdBinary,
 } from "../../vendor/paperclip-runner/index.js";
 import * as issueServiceModule from "../issues.js";
 import {
@@ -174,7 +173,6 @@ vi.mock("../../vendor/paperclip-runner/index.js", async (importOriginal) => {
   >();
   return {
     ...original,
-    defaultCapabilityRunnerdBinary: vi.fn(original.defaultCapabilityRunnerdBinary),
     createNativeSessionBackend: state.createBackend,
     createRunnerdCodexTransport: state.createTransport,
     executeNativeSession: state.execute,
@@ -9650,7 +9648,7 @@ describe("runnerd provider runtime wiring", () => {
     const controllerArtifact = join(isolatedStateDirectory, "paperclip-runnerd");
     if (staleRunner) {
       await writeFile(controllerArtifact, "fixture runner artifact");
-      vi.mocked(defaultCapabilityRunnerdBinary).mockReturnValueOnce(controllerArtifact);
+      state.resolveRunnerBinary.mockReturnValueOnce(controllerArtifact);
     }
     const syncIn = vi.fn(async () => undefined);
     const remoteExecute = vi.fn(
@@ -9726,6 +9724,7 @@ describe("runnerd provider runtime wiring", () => {
       "reached-preinstalled-codex-verification",
     );
     if (staleRunner) {
+      expect(transport.runnerBinary).toBe(controllerArtifact);
       expect(syncIn).toHaveBeenCalledTimes(1);
       expect(syncIn).toHaveBeenCalledWith([expect.objectContaining({
         files: [expect.objectContaining({
diff --git a/server/src/services/native-runtime/native-session-executor.ts b/server/src/services/native-runtime/native-session-executor.ts
index a0b3c1fab36..148a62a5f72 100644
--- a/server/src/services/native-runtime/native-session-executor.ts
+++ b/server/src/services/native-runtime/native-session-executor.ts
@@ -62,7 +62,6 @@ import {
   acpxRuntimeSessionDirectoryName,
   createNativeSessionBackend,
   createRunnerdCodexTransport,
-  defaultCapabilityRunnerdBinary,
   executeNativeSession,
   applyNativeSessionGoalControl,
   inspectWarmRunTransition,
@@ -10432,8 +10431,10 @@ async function createRunnerdBackendWithinSessionClaim(
       }
     }
     if (!usedPreinstalledRunner) {
-      const sourceBinary =
-        explicitRemoteBinary ?? defaultCapabilityRunnerdBinary();
+      // Upload the same artifact used for the controller identity. The server
+      // vendors the runner under vendor/paperclip-runner/bin, so the package
+      // development fallback cannot locate it in a deployed server.
+      const sourceBinary = controllerRunnerBinary;
       if (!existsSync(sourceBinary)) {
         throw new Error("runner_remote_artifact_unavailable");
       }