diff --git a/packages/coding-agent/src/task/executor.ts b/packages/coding-agent/src/task/executor.ts
index 20e3f9ed3..c526cf1c4 100644
--- a/packages/coding-agent/src/task/executor.ts
+++ b/packages/coding-agent/src/task/executor.ts
@@ -2541,7 +2541,7 @@ export async function runSubprocess(options: ExecutorOptions): Promise<SingleRes
 			// artifacts dir) — only the SessionManager differs.
 			const buildSubagentSessionOptions = (sessionManagerForRun: SessionManager): CreateAgentSessionOptions => ({
 				cwd: worktree ?? cwd,
-				additionalDirectories: options.additionalDirectories,
+				additionalDirectories: worktree !== undefined ? undefined : options.additionalDirectories,
 				authStorage,
 				modelRegistry,
 				settings: subagentSettings,