diff --git a/src/main/java/com/alibaba/druid/stat/JdbcSqlStat.java b/src/main/java/com/alibaba/druid/stat/JdbcSqlStat.java
index 77159bd6aa..98caab1c59 100644
--- a/src/main/java/com/alibaba/druid/stat/JdbcSqlStat.java
+++ b/src/main/java/com/alibaba/druid/stat/JdbcSqlStat.java
@@ -178,6 +178,7 @@ public final class JdbcSqlStat implements JdbcSqlStatMBean {
         fetchRowCount.set(0);
 
         histogram.reset();
+        this.lastSlowParameters = null;
         inTransactionCount.set(0);
     }