diff --git a/internal/runtime/executor/codex_executor.go b/internal/runtime/executor/codex_executor.go
index 989a6b93..9eafb6be 100644
--- a/internal/runtime/executor/codex_executor.go
+++ b/internal/runtime/executor/codex_executor.go
@@ -219,10 +219,7 @@ func (e *CodexExecutor) executeCompact(ctx context.Context, auth *cliproxyauth.A
 	body = applyPayloadConfigWithRoot(e.cfg, baseModel, to.String(), "", body, originalTranslated, requestedModel)
 	body, _ = sjson.SetBytes(body, "model", baseModel)
 	body, _ = sjson.DeleteBytes(body, "stream")
-	instructions := gjson.GetBytes(body, "instructions")
-	if !instructions.Exists() || instructions.Type == gjson.Null {
-		body, _ = sjson.SetBytes(body, "instructions", "")
-	}
+	body = normalizeCodexInstructions(body)
 
 	url := strings.TrimSuffix(baseURL, "/") + "/responses/compact"
 	httpReq, err := e.cacheHelper(ctx, from, url, req, body)