diff --git a/.fork-features/manifest.json b/.fork-features/manifest.json
index b7c66fd0ae4b..267b895fd0f2 100644
--- a/.fork-features/manifest.json
+++ b/.fork-features/manifest.json
@@ -165,12 +165,18 @@
     },
     "task-timeout": {
       "status": "active",
-      "description": "Increased default subagent task timeout from 5 minutes to 10 minutes. Upstream default is 5 minutes which is too short for complex tasks like sync operations and multi-file implementations.",
-      "issue": "https://github.com/randomm/opencode/issues/176",
+      "description": "Increased default subagent task timeout from upstream default of 5 minutes to 30 minutes. Both independent timeout constants updated: DEFAULT_TASK_TIMEOUT in async-tasks.ts (background tasks) and taskTimeoutMs in tool/task.ts (sync task execution). 30 minutes needed for complex agentic tasks like multi-file implementations and upstream syncs.",
+      "issue": "https://github.com/randomm/opencode/issues/198",
       "newFiles": [],
       "deletedFiles": [],
-      "modifiedFiles": ["packages/opencode/src/session/async-tasks.ts"],
-      "criticalCode": ["DEFAULT_TASK_TIMEOUT = 10 * 60 * 1000"],
+      "modifiedFiles": [
+        "packages/opencode/src/session/async-tasks.ts",
+        "packages/opencode/src/tool/task.ts"
+      ],
+      "criticalCode": [
+        "DEFAULT_TASK_TIMEOUT = 30 * 60 * 1000",
+        "taskTimeoutMs = 30 * 60 * 1000"
+      ],
       "tests": [],
       "upstreamTracking": {
         "absorptionSignals": ["TASK_TIMEOUT.*config", "task.*timeout.*env", "task_timeout"]
@@ -256,4 +262,4 @@
       }
     }
   }
-}
+}
\ No newline at end of file
diff --git a/packages/opencode/src/session/async-tasks.ts b/packages/opencode/src/session/async-tasks.ts
index ddcab7ed0852..2eb5c86a1334 100644
--- a/packages/opencode/src/session/async-tasks.ts
+++ b/packages/opencode/src/session/async-tasks.ts
@@ -49,7 +49,7 @@ export interface BackgroundTaskResult {
 
 const MAX_STORED_TASK_RESULTS = 1000
 const MAX_DELIVERED_RESULTS = 10000
-const DEFAULT_TASK_TIMEOUT = 10 * 60 * 1000
+const DEFAULT_TASK_TIMEOUT = 30 * 60 * 1000
 const MAX_AGENT_DESCRIPTION_LENGTH = 200
 const MAX_TASK_RESULT_LENGTH = 5000
 const SECONDS_TO_MS_MULTIPLIER = 1000
diff --git a/packages/opencode/src/tool/task.ts b/packages/opencode/src/tool/task.ts
index d17e7b3a4047..9cd9909ec10e 100644
--- a/packages/opencode/src/tool/task.ts
+++ b/packages/opencode/src/tool/task.ts
@@ -378,15 +378,16 @@ export const TaskTool = Tool.define("task", async (initCtx) => {
         release_slot: result.releaseSlot,
       }
 
-      const taskTimeoutMs = 10 * 60 * 1000
-      const syncAbortController = new AbortController()
-      const timeoutPromise = new Promise<never>((_, reject) => {
-        setTimeout(() => {
-          SessionPrompt.cancel(session.id)
-          syncAbortController.abort()
-          reject(new Error("Task timeout after 10 minutes"))
-        }, taskTimeoutMs)
-      })
+const taskTimeoutMs = 30 * 60 * 1000
+const syncAbortController = new AbortController()
+let timeoutTimer: Timer
+const timeoutPromise = new Promise<never>((_, reject) => {
+  timeoutTimer = setTimeout(() => {
+    SessionPrompt.cancel(session.id)
+    syncAbortController.abort()
+    reject(new Error("Task timeout after 30 minutes"))
+  }, taskTimeoutMs)
+})
 
       // Check for abort before sync execution to prevent race condition
       if (ctx.abort.aborted) {
@@ -428,6 +429,7 @@ export const TaskTool = Tool.define("task", async (initCtx) => {
             }),
             timeoutPromise,
           ])
+          clearTimeout(timeoutTimer!)
           const textPart = promptResult.parts.find((p) => p.type === "text" && !p.synthetic)
           const textResult = textPart && "text" in textPart ? textPart.text : undefined
           if (result.releaseSlot) {
@@ -444,6 +446,7 @@ export const TaskTool = Tool.define("task", async (initCtx) => {
             metadata: { sessionId: session.id } as TaskResultMetadata,
           }
         } catch (e) {
+          clearTimeout(timeoutTimer!)
           if (!slotReleased && result.releaseSlot) {
             result.releaseSlot()
             slotReleased = true
diff --git a/packages/opencode/src/tool/task.txt b/packages/opencode/src/tool/task.txt
index 163773e4f8a6..2de18472d612 100644
--- a/packages/opencode/src/tool/task.txt
+++ b/packages/opencode/src/tool/task.txt
@@ -62,7 +62,7 @@ Response Output:
    { "task_id": "task_123", "status": "started", "message": "Task dispatched to @agent" }
    ```
    
-Note: Both modes respect the 5-task limit per session and 10-minute timeout.
+Note: Both modes respect the 5-task limit per session and 30-minute timeout.
 
 Task lifecycle management:
 - If new information makes a running task obsolete, cancel it with cancel_task before launching a replacement. Do not leave stale tasks running.