diff --git a/knn/knn.go b/knn/knn.go
index 38c9e7e..c003a54 100644
--- a/knn/knn.go
+++ b/knn/knn.go
@@ -124,6 +124,12 @@ func (KNN *KNNClassifier) Predict(what base.FixedDataGrid) base.FixedDataGrid {
 		}
 	}
 
+	// If every Attribute is a FloatAttribute, then we remove the last one
+	// because that is the Attribute we are trying to predict.
+	if len(allNumericAttrs) == len(allAttrs) {
+		allNumericAttrs = allNumericAttrs[:len(allNumericAttrs)-1]
+	}
+
 	// Generate return vector
 	ret := base.GeneratePredictionVector(what)