diff --git a/sqlserver.go b/sqlserver.go
index c8cc099..6c4a46d 100644
--- a/sqlserver.go
+++ b/sqlserver.go
@@ -58,5 +58,8 @@ func MSConnect(DBHOST, DBUSER, DBPWD, DBNAME, DBPORT string, conns ...int) error
 }
 
 func CloseMSConn() error {
-	return MSDB_CONN.Close()
+	if MSDB_CONN != nil {
+		return MSDB_CONN.Close()
+	}
+	return nil
 }