diff --git a/src/plugin-config.test.ts b/src/plugin-config.test.ts
index 5e2cd08aa..c1bc3441b 100644
--- a/src/plugin-config.test.ts
+++ b/src/plugin-config.test.ts
@@ -370,4 +370,30 @@ describe("detectUnknownBuiltinAgentKeys", () => {
 
     expect(unknownKeys).toEqual([])
   })
+
+  it("excludes typo keys when explicitly provided", () => {
+    const rawConfig = {
+      agents: {
+        sisyphuss: { model: "openai/gpt-5.2" },
+        translator: { model: "google/gemini-3-flash-preview" },
+      },
+    }
+
+    const unknownKeys = detectUnknownBuiltinAgentKeys(rawConfig, ["sisyphuss"])
+
+    expect(unknownKeys).toEqual(["translator"])
+  })
+
+  it("excludes typo keys case-insensitively", () => {
+    const rawConfig = {
+      agents: {
+        Sisyphuss: { model: "openai/gpt-5.2" },
+        translator: { model: "google/gemini-3-flash-preview" },
+      },
+    }
+
+    const unknownKeys = detectUnknownBuiltinAgentKeys(rawConfig, ["sisyphuss"])
+
+    expect(unknownKeys).toEqual(["translator"])
+  })
 })
diff --git a/src/plugin-config.ts b/src/plugin-config.ts
index 37b3ff49b..c480f9848 100644
--- a/src/plugin-config.ts
+++ b/src/plugin-config.ts
@@ -81,12 +81,21 @@ export function detectLikelyBuiltinAgentTypos(
 
 export function detectUnknownBuiltinAgentKeys(
   rawConfig: Record<string, unknown>,
+  excludeKeys: string[] = [],
 ): string[] {
   const agents = rawConfig.agents;
   if (!agents || typeof agents !== "object") return [];
 
+  const excluded = new Set(excludeKeys.map((key) => key.toLowerCase()));
+
   return Object.keys(agents).filter(
-    (key) => !BUILTIN_AGENT_OVERRIDE_KEYS_BY_LOWER.has(key.toLowerCase()),
+    (key) => {
+      const lower = key.toLowerCase();
+      return (
+        !BUILTIN_AGENT_OVERRIDE_KEYS_BY_LOWER.has(lower)
+        && !excluded.has(lower)
+      );
+    },
   );
 }
 
@@ -194,7 +203,10 @@ export function loadConfigFromPath(
         });
       }
 
-      const unknownAgentKeys = detectUnknownBuiltinAgentKeys(rawConfig);
+      const unknownAgentKeys = detectUnknownBuiltinAgentKeys(
+        rawConfig,
+        typoWarnings.map((warning) => warning.key),
+      );
       if (unknownAgentKeys.length > 0) {
         const unknownKeysMsg = unknownAgentKeys.map((key) => `agents.${key}`).join(", ");
         const migrationHint = "Move custom entries from agents.* to custom_agents.*";