diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index 8fc05fe465e7604a11b4710abf0c2cf6cfe57e52..1b6d94440ccbf56b0f77cafd3a8add9fdf9211a4 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -156,7 +156,7 @@ int32_t tsTsdbMetaCompactRatio = TSDB_META_COMPACT_RATIO;
 // tsdb config 
 // For backward compatibility
 bool    tsdbForceKeepFile = false;
-int32_t tsdbWalFlushSize = TSDB_DEFAULT_WAL_FLUSH_SIZE;  // [0,10000000] MB
+int32_t tsdbWalFlushSize = TSDB_DEFAULT_WAL_FLUSH_SIZE;  // MB
 
 // balance
 int8_t  tsEnableBalance = 1;