diff --git a/packages/durabletask-js/src/orchestration/orchestration-state.ts b/packages/durabletask-js/src/orchestration/orchestration-state.ts
index 2456932..5ff2a6f 100644
--- a/packages/durabletask-js/src/orchestration/orchestration-state.ts
+++ b/packages/durabletask-js/src/orchestration/orchestration-state.ts
@@ -48,5 +48,20 @@ export class OrchestrationState {
         this.failureDetails,
       );
     }
+
+    // Also check the runtime status for cases where failure details were
+    // dropped (e.g., empty error message/type from the sidecar).
+    // Without this check, a FAILED orchestration with missing details would
+    // silently pass through raiseIfFailed().
+    if (this.runtimeStatus === OrchestrationStatus.FAILED) {
+      const syntheticDetails = new FailureDetails(
+        "Unknown error",
+        "UnknownError",
+      );
+      throw new OrchestrationFailedError(
+        `Orchestration '${this.instanceId}' failed: ${syntheticDetails.message}`,
+        syntheticDetails,
+      );
+    }
   }
 }
diff --git a/packages/durabletask-js/test/orchestration-state.spec.ts b/packages/durabletask-js/test/orchestration-state.spec.ts
new file mode 100644
index 0000000..8d2cb4a
--- /dev/null
+++ b/packages/durabletask-js/test/orchestration-state.spec.ts
@@ -0,0 +1,121 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+import { OrchestrationState, OrchestrationStatus, FailureDetails } from "../src";
+import { OrchestrationFailedError } from "../src/orchestration/exception/orchestration-failed-error";
+
+describe("OrchestrationState", () => {
+  const instanceId = "test-instance-001";
+  const name = "TestOrchestrator";
+  const createdAt = new Date("2026-01-01T00:00:00Z");
+  const lastUpdatedAt = new Date("2026-01-01T00:01:00Z");
+
+  function createState(
+    runtimeStatus: OrchestrationStatus,
+    failureDetails?: FailureDetails,
+  ): OrchestrationState {
+    return new OrchestrationState(
+      instanceId,
+      name,
+      runtimeStatus,
+      createdAt,
+      lastUpdatedAt,
+      undefined,
+      undefined,
+      undefined,
+      failureDetails,
+    );
+  }
+
+  describe("raiseIfFailed", () => {
+    it("should throw OrchestrationFailedError when failureDetails is present", () => {
+      const details = new FailureDetails("Something went wrong", "Error", "at foo.ts:1");
+      const state = createState(OrchestrationStatus.FAILED, details);
+
+      expect(() => state.raiseIfFailed()).toThrow(OrchestrationFailedError);
+    });
+
+    it("should include the instance ID and error message when failureDetails is present", () => {
+      const details = new FailureDetails("Something went wrong", "Error");
+      const state = createState(OrchestrationStatus.FAILED, details);
+
+      try {
+        state.raiseIfFailed();
+        throw new Error("Expected raiseIfFailed to throw");
+      } catch (e: unknown) {
+        expect(e).toBeInstanceOf(OrchestrationFailedError);
+        const error = e as OrchestrationFailedError;
+        expect(error.message).toContain(instanceId);
+        expect(error.message).toContain("Something went wrong");
+        expect(error.failureDetails).toBe(details);
+      }
+    });
+
+    it("should throw when runtimeStatus is FAILED but failureDetails is missing", () => {
+      const state = createState(OrchestrationStatus.FAILED);
+
+      expect(() => state.raiseIfFailed()).toThrow(OrchestrationFailedError);
+    });
+
+    it("should include the instance ID when runtimeStatus is FAILED without details", () => {
+      const state = createState(OrchestrationStatus.FAILED);
+
+      try {
+        state.raiseIfFailed();
+        throw new Error("Expected raiseIfFailed to throw");
+      } catch (e: unknown) {
+        expect(e).toBeInstanceOf(OrchestrationFailedError);
+        const error = e as OrchestrationFailedError;
+        expect(error.message).toContain(instanceId);
+        expect(error.failureDetails).toBeDefined();
+        expect(error.failureDetails.errorType).toEqual("UnknownError");
+      }
+    });
+
+    it("should not throw when runtimeStatus is COMPLETED", () => {
+      const state = createState(OrchestrationStatus.COMPLETED);
+
+      expect(() => state.raiseIfFailed()).not.toThrow();
+    });
+
+    it("should not throw when runtimeStatus is RUNNING", () => {
+      const state = createState(OrchestrationStatus.RUNNING);
+
+      expect(() => state.raiseIfFailed()).not.toThrow();
+    });
+
+    it("should not throw when runtimeStatus is TERMINATED", () => {
+      const state = createState(OrchestrationStatus.TERMINATED);
+
+      expect(() => state.raiseIfFailed()).not.toThrow();
+    });
+
+    it("should not throw when runtimeStatus is PENDING", () => {
+      const state = createState(OrchestrationStatus.PENDING);
+
+      expect(() => state.raiseIfFailed()).not.toThrow();
+    });
+
+    it("should not throw when runtimeStatus is SUSPENDED", () => {
+      const state = createState(OrchestrationStatus.SUSPENDED);
+
+      expect(() => state.raiseIfFailed()).not.toThrow();
+    });
+
+    it("should prioritize failureDetails over synthetic details when both are available", () => {
+      const details = new FailureDetails("Specific error", "CustomError", "stack trace");
+      const state = createState(OrchestrationStatus.FAILED, details);
+
+      try {
+        state.raiseIfFailed();
+        throw new Error("Expected raiseIfFailed to throw");
+      } catch (e: unknown) {
+        const error = e as OrchestrationFailedError;
+        // Should use the real failure details, not synthetic ones
+        expect(error.failureDetails.message).toEqual("Specific error");
+        expect(error.failureDetails.errorType).toEqual("CustomError");
+        expect(error.failureDetails.stackTrace).toEqual("stack trace");
+      }
+    });
+  });
+});