diff --git a/src/tools/delegate-task/executor.ts b/src/tools/delegate-task/executor.ts
index 8d2a75fed..df761c08d 100644
--- a/src/tools/delegate-task/executor.ts
+++ b/src/tools/delegate-task/executor.ts
@@ -793,16 +793,20 @@ export async function resolveCategoryExecution(
   let modelInfo: ModelFallbackInfo | undefined
   let categoryModel: { providerID: string; modelID: string; variant?: string } | undefined
 
+  const overrideModel = sisyphusJuniorModel
+
   if (!requirement) {
-    actualModel = resolved.model
+    actualModel = overrideModel ?? resolved.model
     if (actualModel) {
-      modelInfo = { model: actualModel, type: "system-default", source: "system-default" }
+      modelInfo = overrideModel
+        ? { model: actualModel, type: "user-defined", source: "override" }
+        : { model: actualModel, type: "system-default", source: "system-default" }
     }
   } else {
     const resolution = resolveModelPipeline({
       intent: {
-        userModel: userCategories?.[args.category!]?.model,
-        categoryDefaultModel: resolved.model ?? sisyphusJuniorModel,
+        userModel: overrideModel ?? userCategories?.[args.category!]?.model,
+        categoryDefaultModel: resolved.model,
       },
       constraints: { availableModels },
       policy: {
diff --git a/src/tools/delegate-task/tools.test.ts b/src/tools/delegate-task/tools.test.ts
index d88d362b8..22bf5d984 100644
--- a/src/tools/delegate-task/tools.test.ts
+++ b/src/tools/delegate-task/tools.test.ts
@@ -1711,6 +1711,65 @@ describe("sisyphus-task", () => {
       expect(launchInput.model.providerID).toBe("anthropic")
       expect(launchInput.model.modelID).toBe("claude-haiku-4-5")
     })
+
+    test("sisyphus-junior model override takes precedence over category model", async () => {
+      // given - sisyphus-junior override model differs from category default
+      const { createDelegateTask } = require("./tools")
+      let launchInput: any
+
+      const mockManager = {
+        launch: async (input: any) => {
+          launchInput = input
+          return {
+            id: "task-override",
+            sessionID: "ses_override_test",
+            description: "Override precedence test",
+            agent: "sisyphus-junior",
+            status: "running",
+          }
+        },
+      }
+
+      const mockClient = {
+        app: { agents: async () => ({ data: [] }) },
+        config: { get: async () => ({ data: { model: SYSTEM_DEFAULT_MODEL } }) },
+        model: { list: async () => [] },
+        session: {
+          create: async () => ({ data: { id: "test-session" } }),
+          prompt: async () => ({ data: {} }),
+          messages: async () => ({ data: [] }),
+        },
+      }
+
+      const tool = createDelegateTask({
+        manager: mockManager,
+        client: mockClient,
+        sisyphusJuniorModel: "anthropic/claude-sonnet-4-5",
+      })
+
+      const toolContext = {
+        sessionID: "parent-session",
+        messageID: "parent-message",
+        agent: "sisyphus",
+        abort: new AbortController().signal,
+      }
+
+      // when - using ultrabrain category (default model is openai/gpt-5.2-codex)
+      await tool.execute(
+        {
+          description: "Override precedence test",
+          prompt: "Do something",
+          category: "ultrabrain",
+          run_in_background: true,
+          load_skills: [],
+        },
+        toolContext
+      )
+
+      // then - override model should be used instead of category model
+      expect(launchInput.model.providerID).toBe("anthropic")
+      expect(launchInput.model.modelID).toBe("claude-sonnet-4-5")
+    })
   })
 
   describe("browserProvider propagation", () => {