diff --git a/src/tsdb/inc/tsdbMain.h b/src/tsdb/inc/tsdbMain.h
index ba5711a81c580f271589fefaf5a7a54fea0d05c3..762d2253e21aca6c95318cdbcda16a31da9b45cf 100644
--- a/src/tsdb/inc/tsdbMain.h
+++ b/src/tsdb/inc/tsdbMain.h
@@ -263,7 +263,9 @@ typedef struct {
   TSKEY      minKey;
   TSKEY      maxKey;
   SFileGroup fGroup;
-  SFile      nIdxF;
+#ifdef TSDB_IDX
+  SFile nIdxF;
+#endif
   SFile      nHeadF;
   SFile      nLastF;
 } SHelperFile;