diff --git a/packages/adapters/claude-local/src/server/parse.test.ts b/packages/adapters/claude-local/src/server/parse.test.ts
index 2c88106f..d8cd65b0 100644
--- a/packages/adapters/claude-local/src/server/parse.test.ts
+++ b/packages/adapters/claude-local/src/server/parse.test.ts
@@ -3,6 +3,7 @@ import {
   extractClaudeRetryNotBefore,
   isClaudeTransientUpstreamError,
   isClaudePoisonedPreviousMessageIdError,
+  isClaudeUnknownSessionError,
 } from "./parse.js";
 
 describe("isClaudeTransientUpstreamError", () => {
@@ -144,6 +145,46 @@ describe("isClaudePoisonedPreviousMessageIdError", () => {
   });
 });
 
+describe("isClaudeUnknownSessionError", () => {
+  it("detects the legacy 'no conversation found' message", () => {
+    expect(
+      isClaudeUnknownSessionError({
+        result: "Error: No conversation found with session id 1234",
+      }),
+    ).toBe(true);
+  });
+
+  it("detects 'session ... not found' style errors", () => {
+    expect(
+      isClaudeUnknownSessionError({
+        errors: [{ message: "Session abc123 not found" }],
+      }),
+    ).toBe(true);
+  });
+
+  it("detects '--resume requires a valid session' validation error from non-UUID input", () => {
+    expect(
+      isClaudeUnknownSessionError({
+        errors: [
+          {
+            message:
+              'Error: --resume requires a valid session ID or session title when used with --print. Usage: claude -p --resume <session-id|title>. Provided value "ses_268c2d0a5ffemYbEaeG7c86Uvo" is not a UUID and does not match any session title.',
+          },
+        ],
+      }),
+    ).toBe(true);
+  });
+
+  it("returns false for unrelated error text", () => {
+    expect(
+      isClaudeUnknownSessionError({
+        result: "Some other failure",
+        errors: [{ message: "Network timeout" }],
+      }),
+    ).toBe(false);
+  });
+});
+
 describe("extractClaudeRetryNotBefore", () => {
   it("parses the 'resets 4pm' hint in its explicit timezone", () => {
     const now = new Date("2026-04-22T15:15:00.000Z");
diff --git a/packages/adapters/claude-local/src/server/parse.ts b/packages/adapters/claude-local/src/server/parse.ts
index 6fee0d84..36d13fd6 100644
--- a/packages/adapters/claude-local/src/server/parse.ts
+++ b/packages/adapters/claude-local/src/server/parse.ts
@@ -192,7 +192,9 @@ export function isClaudeUnknownSessionError(parsed: Record<string, unknown>): bo
     .filter(Boolean);
 
   return allMessages.some((msg) =>
-    /no conversation found with session id|unknown session|session .* not found|not a valid UUID/i.test(msg),
+    /no conversation found with session id|unknown session|session .* not found|not a valid UUID|--resume requires a valid session|is not a UUID|does not match any session title/i.test(
+      msg,
+    ),
   );
 }