diff --git a/src/client/jTPCCConnection.java b/src/client/jTPCCConnection.java
index bb36623..912694e 100644
--- a/src/client/jTPCCConnection.java
+++ b/src/client/jTPCCConnection.java
@@ -316,6 +316,8 @@ public void commit()
     public void rollback()
 	throws SQLException
     {
+	if (!dbConn.isClosed()) {
 	dbConn.rollback();
+	}
     }
 }