diff --git a/components-core/src/main/java/org/dllearner/refinementoperators/OperatorInverter.java b/components-core/src/main/java/org/dllearner/refinementoperators/OperatorInverter.java
index 375e13bc65..660e3e6028 100644
--- a/components-core/src/main/java/org/dllearner/refinementoperators/OperatorInverter.java
+++ b/components-core/src/main/java/org/dllearner/refinementoperators/OperatorInverter.java
@@ -80,6 +80,7 @@ public void setGuaranteeLength(boolean guaranteeLength) {
 	
 	public OperatorInverter(LengthLimitedRefinementOperator operator) {
 		this.operator = operator;
+		this.lengthMetric = operator.getLengthMetric();
 	}
 
 	public OperatorInverter() {