diff --git a/src/main/runtime/agent-session-record-conversation-name.test.ts b/src/main/runtime/agent-session-record-conversation-name.test.ts
index de0ef7c2eaf..3c5c55d83c6 100644
--- a/src/main/runtime/agent-session-record-conversation-name.test.ts
+++ b/src/main/runtime/agent-session-record-conversation-name.test.ts
@@ -33,6 +33,18 @@ describe('agent session record conversationName validation', () => {
       false
     )
   })
+
+  it('rejects persisted names that bypassed canonical normalization', () => {
+    expect(
+      isAgentSessionRecord({
+        ...agentSessionRecordFixture(),
+        conversationName: 'Fix\u202Egnp.exe probe'
+      })
+    ).toBe(false)
+    expect(
+      isAgentSessionRecord({ ...agentSessionRecordFixture(), conversationName: 'Fix\nthe probe' })
+    ).toBe(false)
+  })
 })
 
 describe('setAgentSessionRecordConversationName', () => {
diff --git a/src/shared/agent-session-conversation-name.test.ts b/src/shared/agent-session-conversation-name.test.ts
index 4191cf5265d..aa824e5f042 100644
--- a/src/shared/agent-session-conversation-name.test.ts
+++ b/src/shared/agent-session-conversation-name.test.ts
@@ -38,10 +38,13 @@ describe('normalizeAgentSessionConversationName', () => {
 })
 
 describe('isAgentSessionConversationName', () => {
-  it('accepts a bounded non-empty string and nothing else', () => {
+  it('accepts only bounded canonical names', () => {
     expect(isAgentSessionConversationName('Fix the probe')).toBe(true)
     expect(isAgentSessionConversationName('')).toBe(false)
     expect(isAgentSessionConversationName('a'.repeat(201))).toBe(false)
+    expect(isAgentSessionConversationName(' Fix the probe ')).toBe(false)
+    expect(isAgentSessionConversationName('Fix\nthe probe')).toBe(false)
+    expect(isAgentSessionConversationName('Fix\u202Egnp.exe probe')).toBe(false)
     expect(isAgentSessionConversationName(7)).toBe(false)
   })
 })
diff --git a/src/shared/agent-session-conversation-name.ts b/src/shared/agent-session-conversation-name.ts
index 8df01c3d6f6..039721bfee2 100644
--- a/src/shared/agent-session-conversation-name.ts
+++ b/src/shared/agent-session-conversation-name.ts
@@ -61,6 +61,7 @@ export function isAgentSessionConversationName(value: unknown): value is string
   return (
     typeof value === 'string' &&
     value.length > 0 &&
-    value.length <= AGENT_SESSION_CONVERSATION_NAME_MAX_LENGTH
+    value.length <= AGENT_SESSION_CONVERSATION_NAME_MAX_LENGTH &&
+    normalizeAgentSessionConversationName(value) === value
   )
 }