diff --git a/openbis_knime/source/java/ch/systemsx/cisd/openbis/knime/query/QueryNodeModel.java b/openbis_knime/source/java/ch/systemsx/cisd/openbis/knime/query/QueryNodeModel.java
index 9f6077ead972e644500e55368100d551811101fe..e6f04afb28dac36ee320ecfe7748b97a87ba1bd6 100644
--- a/openbis_knime/source/java/ch/systemsx/cisd/openbis/knime/query/QueryNodeModel.java
+++ b/openbis_knime/source/java/ch/systemsx/cisd/openbis/knime/query/QueryNodeModel.java
@@ -22,7 +22,6 @@ import java.io.Serializable;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 
 import org.knime.core.data.DataCell;
 import org.knime.core.data.DataTableSpec;