diff --git a/src/evm/EvmoleFailures.test.ts b/src/evm/EvmoleFailures.test.ts
new file mode 100644
index 0000000000..0a1f44fb2b
--- /dev/null
+++ b/src/evm/EvmoleFailures.test.ts
@@ -0,0 +1,71 @@
+import { expect, it } from "vitest";
+import { evmInterfaceFailure } from "./EvmoleFailures.js";
+import { OwnedCommandFailure } from "../process/OwnedCommand.js";
+import { AnalysisCancelledError } from "../domain/analysisErrorCore.js";
+import type { ProviderProcessSnapshot } from "../process/ProviderProcess.js";
+
+const snapshot: ProviderProcessSnapshot = {
+  stdout: { text: "selected output", bytes: 15, observedBytes: 15 },
+  stderr: { text: "warning", bytes: 7, observedBytes: 7 },
+  exitCode: 0,
+  signal: null,
+};
+
+it.each([
+  undefined,
+  null,
+  "caller stopped",
+  { requested: "stop" },
+  new AnalysisCancelledError("foreign", {
+    cleanup: { reason: "foreign owner", resources: ["foreign-resource"] },
+  }),
+])(
+  "retains the exact command cancellation reason as opaque data: %j",
+  (reason) => {
+    const source = new OwnedCommandFailure(
+      "cancelled",
+      "cancelled",
+      snapshot,
+      null,
+      {
+        cancellation: { reason },
+      },
+    );
+    const result = evmInterfaceFailure(source, "worker", "/selected.hex");
+    expect(result).toBeInstanceOf(AnalysisCancelledError);
+    expect(result.cause).toBe(reason);
+    expect(result.capturedOutput).toEqual({
+      stdout: "selected output",
+      stderr: "warning",
+      truncated: false,
+    });
+    expect(result.cleanupIncomplete).toBe(false);
+  },
+);
+
+it.each([
+  { failure: "process" as const, cleanup: null, tag: "ProviderAdapterError" },
+  { failure: "timeout" as const, cleanup: null, tag: "AnalysisTimeoutError" },
+  {
+    failure: "cancelled" as const,
+    cleanup: "close refused",
+    tag: "ProviderAdapterError",
+  },
+])("keeps $tag ahead of recorded cancellation", ({ failure, cleanup, tag }) => {
+  const source = new OwnedCommandFailure(
+    failure,
+    "physical outcome",
+    snapshot,
+    cleanup,
+    {
+      cancellation: { reason: "later interruption" },
+    },
+    ["exact-owner"],
+  );
+  const result = evmInterfaceFailure(source, "worker", "/selected.hex");
+  expect(result._tag).toBe(tag);
+  if (cleanup !== null) {
+    expect(result.cleanupIncomplete).toBe(true);
+    expect(result.cleanupResources).toEqual(["exact-owner"]);
+  }
+});
diff --git a/src/evm/EvmoleFailures.ts b/src/evm/EvmoleFailures.ts
index da1bae8d85..683a828f1a 100644
--- a/src/evm/EvmoleFailures.ts
+++ b/src/evm/EvmoleFailures.ts
@@ -68,6 +68,7 @@ export const evmInterfaceFailure = (
       );
     if (cause.reason === "cancelled")
       return new AnalysisCancelledError("inspect_evm_interface", {
+        cause: cause.cancellation?.reason,
         ...outputOptions,
         ...cleanupOptions,
       });