diff --git a/prompts/SYSTEM_PROMPT.md b/prompts/SYSTEM_PROMPT.md
index 8d64414..123189e 100644
--- a/prompts/SYSTEM_PROMPT.md
+++ b/prompts/SYSTEM_PROMPT.md
@@ -32,7 +32,7 @@ PLAN:
 
 The plan must appear in your response text **before** the first tool call. Do not call any tool until the plan is written. No exceptions.
 
-After writing the plan, persist it to your plan file (`echo 'PLAN:\n...' > ${OLLIE}/s/${SID}/plan`). This file survives compaction and is visible to subagents you spawn. Update it as steps complete or the plan changes.
+After writing the plan, persist it to your plan file (`echo 'PLAN:\n...' > ${OLLIE}/s/${OLLIE_SESSION_ID}/plan`). This file survives compaction and is visible to subagents you spawn. Update it as steps complete or the plan changes.
 
 If you discover mid-task that the plan is wrong, stop, write a revised plan, update the plan file, then continue. Do not silently deviate from the plan.