diff --git a/pom.xml b/pom.xml
index 2f1e1e9c9151f87f44dbaec0d9f2524a28451c3a..a2a3da8b17979730267164d0005d26d00b373753 100644
--- a/pom.xml
+++ b/pom.xml
@@ -47,9 +47,9 @@
         <spring-data-jpa.version>1.10.11.RELEASE</spring-data-jpa.version>
         <spring-boot-starter-actuator.version>1.4.7.RELEASE</spring-boot-starter-actuator.version>
         <aspectjweaver.version>1.8.9</aspectjweaver.version>
-        <woken-messages.version>2.9.4</woken-messages.version>
+        <woken-messages.version>2.9.5</woken-messages.version>
         <javax-inject.version>1</javax-inject.version>
-        <akka.version>2.5.19</akka.version>
+        <akka.version>2.5.20</akka.version>
         <spring-context.version>4.3.4.RELEASE</spring-context.version>
         <protobuf-java.version>3.1.0</protobuf-java.version>
 
diff --git a/src/main/java/eu/hbp/mip/model/Experiment.java b/src/main/java/eu/hbp/mip/model/Experiment.java
index 5fb1e24a78a929641a5a3010946d812bfd60dcf1..90b24e1f5943a9e1b2da86a02864f63f22543947 100644
--- a/src/main/java/eu/hbp/mip/model/Experiment.java
+++ b/src/main/java/eu/hbp/mip/model/Experiment.java
@@ -123,9 +123,9 @@ public class Experiment {
         scala.collection.immutable.List<ValidationSpec> validationsSeq = JavaConversions.asScalaBuffer(validations).toList();
 
         WokenConversions conv = new WokenConversions();
-        scala.collection.immutable.Set<DatasetId> trainingDatasets = conv.toDatasets(model.getQuery().getTrainingDatasets());
-        scala.collection.immutable.Set<DatasetId> testingDatasets = conv.toDatasets(model.getQuery().getTestingDatasets());
-        scala.collection.immutable.Set<DatasetId> validationDatasets = conv.toDatasets(model.getQuery().getValidationDatasets());
+        scala.collection.immutable.SortedSet<DatasetId> trainingDatasets = conv.toDatasets(model.getQuery().getTrainingDatasets());
+        scala.collection.immutable.SortedSet<DatasetId> testingDatasets = conv.toDatasets(model.getQuery().getTestingDatasets());
+        scala.collection.immutable.SortedSet<DatasetId> validationDatasets = conv.toDatasets(model.getQuery().getValidationDatasets());
 
         String filtersJson = model.getQuery().getFilters();
         Option<FilterRule> filters = conv.toFilterRule(filtersJson);
diff --git a/src/main/java/eu/hbp/mip/model/MiningQuery.java b/src/main/java/eu/hbp/mip/model/MiningQuery.java
index 5ad30ea89fd1c246647f8f62aff9d79f07040a06..016899377030f8fb767d22083d338aa98ff8a509 100644
--- a/src/main/java/eu/hbp/mip/model/MiningQuery.java
+++ b/src/main/java/eu/hbp/mip/model/MiningQuery.java
@@ -101,7 +101,7 @@ public class MiningQuery {
         UserId userId = new UserId(user);
 
         WokenConversions conv = new WokenConversions();
-        scala.collection.immutable.Set<DatasetId> datasets = conv.toDatasets(getDatasets());
+        scala.collection.immutable.SortedSet<DatasetId> datasets = conv.toDatasets(getDatasets());
         String filtersJson = getFilters();
         Option<FilterRule> filters = conv.toFilterRule(filtersJson);
 
diff --git a/src/main/scala/ch.chuv.lren/mip/portal/WokenConversions.scala b/src/main/scala/ch.chuv.lren/mip/portal/WokenConversions.scala
index a6b695e05f9828c0eb9f7593311c93356e42ad1d..a0240df7d4bf4111be1ae4819266a6a120f377df 100644
--- a/src/main/scala/ch.chuv.lren/mip/portal/WokenConversions.scala
+++ b/src/main/scala/ch.chuv.lren/mip/portal/WokenConversions.scala
@@ -9,6 +9,7 @@ import org.springframework.stereotype.Component
 import spray.json._
 
 import scala.collection.JavaConverters._
+import scala.collection.immutable.{SortedSet, TreeSet}
 
 @Component
 class WokenConversions {
@@ -18,8 +19,8 @@ class WokenConversions {
     case _ => Some(json).map(_.parseJson.convertTo[FilterRule])
   }
 
-  def toDatasets(datasets: java.util.List[Variable]): Set[DatasetId] =
-    datasets.asScala.map(v => DatasetId(v.getCode)).toSet
+  def toDatasets(datasets: java.util.List[Variable]): SortedSet[DatasetId] =
+    datasets.asScala.map(v => DatasetId(v.getCode)).toSet.to[TreeSet]
 
   def toSqlWhere(filter: Option[FilterRule]): String = filter.fold("")(_.toSqlWhere)