diff --git a/pmml-sklearn/src/main/java/sklearn/EstimatorUtil.java b/pmml-sklearn/src/main/java/sklearn/EstimatorUtil.java
index 64dea54e..09646ac9 100644
--- a/pmml-sklearn/src/main/java/sklearn/EstimatorUtil.java
+++ b/pmml-sklearn/src/main/java/sklearn/EstimatorUtil.java
@@ -153,7 +153,7 @@ public List<Feature> export(Estimator estimator, String predictFunc, Schema sche
 
 							OutputField outputField = Iterables.getLast(predictionOutputFields);
 
-							return encoder.export(model, outputField.getName());
+							return encoder.export(model, outputField.requireName());
 						} else
 
 						{
diff --git a/pmml-sklearn/src/main/java/sklearn/calibration/CalibratedClassifier.java b/pmml-sklearn/src/main/java/sklearn/calibration/CalibratedClassifier.java
index 96566414..0e1d5166 100644
--- a/pmml-sklearn/src/main/java/sklearn/calibration/CalibratedClassifier.java
+++ b/pmml-sklearn/src/main/java/sklearn/calibration/CalibratedClassifier.java
@@ -140,7 +140,7 @@ public Model encodeModel(Schema schema){
 					}
 
 					// XXX
-					outputField.setName(getDecisionFunctionField(outputField.getName()));
+					outputField.setName(getDecisionFunctionField(outputField.requireName()));
 
 					models.add(decisionFunctionModel);