diff --git a/packages/rivetkit/src/drivers/engine/actor-driver.ts b/packages/rivetkit/src/drivers/engine/actor-driver.ts
index 10e7fd514..d08e22249 100644
--- a/packages/rivetkit/src/drivers/engine/actor-driver.ts
+++ b/packages/rivetkit/src/drivers/engine/actor-driver.ts
@@ -177,16 +177,9 @@ export class EngineActorDriver implements ActorDriver {
 	async readPersistedData(actorId: string): Promise<Uint8Array | undefined> {
 		const handler = this.#actors.get(actorId);
 		if (!handler) throw new Error(`Actor ${actorId} not loaded`);
-		if (handler.persistedData) return handler.persistedData;
 
-		const [value] = await this.#runner.kvGet(actorId, [KEYS.PERSIST_DATA]);
-
-		if (value !== null) {
-			handler.persistedData = value;
-			return value;
-		} else {
-			return undefined;
-		}
+		// This was loaded during actor startup
+		return handler.persistedData;
 	}
 
 	async writePersistedData(actorId: string, data: Uint8Array): Promise<void> {
@@ -251,11 +244,24 @@ export class EngineActorDriver implements ActorDriver {
 		// Get or create handler
 		let handler = this.#actors.get(actorId);
 		if (!handler) {
+			// IMPORTANT: We must set the handler in the map synchronously before doing any
+			// async operations to avoid race conditions where multiple calls might try to
+			// create the same handler simultaneously.
 			handler = {
 				actorStartPromise: promiseWithResolvers(),
-				persistedData: serializeEmptyPersistData(input),
+				persistedData: undefined,
 			};
 			this.#actors.set(actorId, handler);
+
+			// Load persisted data from storage
+			const [persistedValue] = await this.#runner.kvGet(actorId, [
+				KEYS.PERSIST_DATA,
+			]);
+
+			handler.persistedData =
+				persistedValue !== null
+					? persistedValue
+					: serializeEmptyPersistData(input);
 		}
 
 		const name = runConfig.name as string;
diff --git a/packages/rivetkit/src/manager/router.ts b/packages/rivetkit/src/manager/router.ts
index f468df105..4d2e1fed0 100644
--- a/packages/rivetkit/src/manager/router.ts
+++ b/packages/rivetkit/src/manager/router.ts
@@ -641,7 +641,7 @@ function addManagerRoutes(
 		});
 	}
 
-	router.get("/health", (c) => handleHealthRequest(c, runConfig));
+	router.get("/health", (c) => handleHealthRequest(c));
 
 	router.get("/metadata", (c) => handleMetadataRequest(c, runConfig));
 
diff --git a/packages/rivetkit/tests/driver-engine.test.ts b/packages/rivetkit/tests/driver-engine.test.ts
index f33f5a0e2..74a0dfab5 100644
--- a/packages/rivetkit/tests/driver-engine.test.ts
+++ b/packages/rivetkit/tests/driver-engine.test.ts
@@ -18,9 +18,10 @@ runDriverTests({
 			join(__dirname, "../fixtures/driver-test-suite/registry.ts"),
 			async (registry) => {
 				// Get configuration from environment or use defaults
-				const endpoint = process.env.RIVET_ENDPOINT || "http://localhost:6420";
+				const endpoint = process.env.RIVET_ENDPOINT || "http://127.0.0.1:6420";
 				const namespace = `test-${crypto.randomUUID().slice(0, 8)}`;
 				const runnerName = "test-runner";
+				const token = "dev";
 
 				// Create namespace
 				const response = await fetch(`${endpoint}/namespaces`, {
@@ -44,6 +45,10 @@ runDriverTests({
 				// Start the actor driver
 				const runConfig = RunnerConfigSchema.parse({
 					driver: driverConfig,
+					endpoint,
+					namespace,
+					runnerName,
+					token,
 					getUpgradeWebSocket: () => undefined,
 				});
 				const managerDriver = driverConfig.manager(registry.config, runConfig);
@@ -55,12 +60,14 @@ runDriverTests({
 					inlineClient,
 				);
 
+				await new Promise((resolve) => setTimeout(resolve, 1000));
+
 				return {
 					rivetEngine: {
 						endpoint: "http://127.0.0.1:6420",
 						namespace: namespace,
 						runnerName: runnerName,
-						token: "dev",
+						token,
 					},
 					driver: driverConfig,
 					cleanup: async () => {