NoSuchMethodError at runtime while comparing org.joda.time.DateTime instances

Given the following rule:

—
import org.joda.time.DateTime;

rule "in the past"
when
exists DateTime( this < new DateTime() )
then
System.out.println("in the past");
end
—

I obtain this exception at runtime while comparing a large number of DateTimes:

// java.lang.NoSuchMethodError: org.joda.time.DateTime.compareTo(Lorg/joda/time/DateTime;)I
// at ConditionEvaluatorc959ae5f82e8456f9e4f2d8b7e07b19d.evaluate(Unknown Source)
// at org.drools.core.rule.constraint.MvelConstraint.evaluate(MvelConstraint.java:217)
// at org.drools.core.rule.constraint.MvelConstraint.isAllowed(MvelConstraint.java:174)
// at org.drools.core.phreak.PhreakFromNode.checkConstraintsAndPropagate(PhreakFromNode.java:298)
// at org.drools.core.phreak.PhreakFromNode.doLeftInserts(PhreakFromNode.java:101)
// at org.drools.core.phreak.PhreakFromNode.doNode(PhreakFromNode.java:49)
// at org.drools.core.phreak.RuleNetworkEvaluator.innerEval(RuleNetworkEvaluator.java:348)
// at org.drools.core.phreak.RuleNetworkEvaluator.doRiaNode(RuleNetworkEvaluator.java:604)
// at org.drools.core.phreak.RuleNetworkEvaluator.evalBetaNode(RuleNetworkEvaluator.java:528)
// at org.drools.core.phreak.RuleNetworkEvaluator.innerEval(RuleNetworkEvaluator.java:334)