Aries transaction manager fails with background connection validation

<bean id="ariesTransactionManager" class="org.apache.aries.transaction.internal.AriesTransactionManagerImpl">
        ...    
</bean>
 <bean id="internalXaDataSource" class="org.h2.jdbcx.JdbcDataSource">
        <property name="URL" value="..."/>
        <property name="description" value="..."/>
    </bean>
    <bean id="dataSource" class="org.apache.aries.transaction.jdbc.RecoverableDataSource" init-method="start">
        <property name="transactionManager" ref="ariesTransactionManager"/>
        <property name="dataSource" ref="internalXaDataSource"/>
        <property name="backgroundValidation" value="true"/>
        <property name="transaction" value="xa"/>
        ...    
</bean>

Caused by: java.lang.RuntimeException: java.lang.NoSuchFieldException: pool
	at org.apache.aries.transaction.jdbc.internal.Reflections.get(Reflections.java:56)
	at org.apache.aries.transaction.jdbc.internal.ValidatingGenericConnectionManager.<init>(ValidatingGenericConnectionManager.java:89)
	at org.apache.aries.transaction.jdbc.internal.ConnectionManagerFactory.init(ConnectionManagerFactory.java:152)
	at org.apache.aries.transaction.jdbc.RecoverableDataSource.start(RecoverableDataSource.java:235)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)

  if (current instanceof AbstractSinglePoolConnectionInterceptor) {
            foundPool = Reflections.get(stack, "pool"); //----- PROBLEM!
        } else if (current instanceof MultiPoolConnectionInterceptor) {
            log.warn("validation on stack {} not supported", stack);
        }