diff --git a/src/main/java/com/googlesource/gerrit/plugins/task/Properties.java b/src/main/java/com/googlesource/gerrit/plugins/task/Properties.java
index ff8dfad..ed38fb3 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/task/Properties.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/task/Properties.java
@@ -18,8 +18,6 @@
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gwtorm.server.OrmException;
-import com.googlesource.gerrit.plugins.task.TaskConfig.NamesFactory;
-import com.googlesource.gerrit.plugins.task.TaskConfig.Task;
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -32,25 +30,42 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-/** Use to expand properties like ${_name} for a Task Definition. */
+/** Use to expand properties like ${_name} in the text of various definitions. */
 public class Properties {
-  public Properties(ChangeData changeData, Task definition, Map<String, String> parentProperties)
-      throws OrmException {
-    Map<String, String> expanded = new HashMap<>(parentProperties);
-    expanded.putAll(getInternalProperties(definition, changeData));
-    new RecursiveExpander(expanded).expand(definition.getAllProperties());
+  /** Use to expand properties specifically for Tasks. */
+  public static class Task extends Expander {
+    public static final Task EMPTY_PARENT = new Task();
 
-    definition.setExpandedProperties(expanded);
+    public Task() {
+      super(Collections.emptyMap());
+    }
 
-    new Expander(expanded).expandFieldValues(definition, Collections.emptySet());
+    public Task(ChangeData changeData, TaskConfig.Task definition, Task parentProperties)
+        throws OrmException {
+      super(parentProperties.forDescendants());
+      valueByName.putAll(getInternalProperties(definition, changeData));
+      new RecursiveExpander(valueByName).expand(definition.getAllProperties());
+
+      definition.setExpandedProperties(valueByName);
+
+      expandFieldValues(definition, Collections.emptySet());
+    }
+
+    protected Map<String, String> forDescendants() {
+      return new HashMap<>(valueByName);
+    }
   }
 
-  public Properties(NamesFactory namesFactory, Map<String, String> properties) {
-    new Expander(properties).expandFieldValues(namesFactory, Sets.newHashSet(TaskConfig.KEY_TYPE));
+  /** Use to expand properties specifically for NamesFactories. */
+  public static class NamesFactory extends Expander {
+    public NamesFactory(TaskConfig.NamesFactory namesFactory, Task properties) {
+      super(properties.valueByName);
+      expandFieldValues(namesFactory, Sets.newHashSet(TaskConfig.KEY_TYPE));
+    }
   }
 
-  protected static Map<String, String> getInternalProperties(Task definition, ChangeData changeData)
-      throws OrmException {
+  protected static Map<String, String> getInternalProperties(
+      TaskConfig.Task definition, ChangeData changeData) throws OrmException {
     Map<String, String> properties = new HashMap<>();
 
     properties.put("_name", definition.name);
diff --git a/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java b/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java
index b1e686b..f1979a3 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java
@@ -39,11 +39,9 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 
@@ -97,7 +95,6 @@
     protected LinkedList<String> path = new LinkedList<>();
     protected List<Node> nodes;
     protected Set<String> names = new HashSet<>();
-    protected Map<String, String> properties;
 
     protected void addSubDefinitions(List<Task> defs) {
       for (Task def : defs) {
@@ -111,7 +108,7 @@
         // path check above detects looping definitions
         // names check above detects duplicate subtasks
         try {
-          node = new Node(def, path, properties);
+          node = new Node(def, path, getProperties());
         } catch (Exception e) {
         } // bad definition, handled with null
       }
@@ -121,13 +118,13 @@
     public ChangeData getChangeData() {
       return TaskTree.this.changeData;
     }
+
+    protected Properties.Task getProperties() {
+      return Properties.Task.EMPTY_PARENT;
+    }
   }
 
   protected class Root extends NodeList {
-    protected Root() {
-      properties = new HashMap<String, String>();
-    }
-
     public List<Node> getRootNodes() throws ConfigInvalidException, IOException {
       if (nodes == null) {
         nodes = new ArrayList<>();
@@ -143,15 +140,15 @@
 
   public class Node extends NodeList {
     public final Task task;
+    protected final Properties.Task properties;
 
-    public Node(Task definition, List<String> path, Map<String, String> parentProperties)
+    public Node(Task definition, List<String> path, Properties.Task parentProperties)
         throws ConfigInvalidException, OrmException {
       this.task = definition;
       this.path.addAll(path);
       this.path.add(definition.name);
       Preloader.preload(definition);
-      new Properties(getChangeData(), definition, parentProperties);
-      properties = definition.properties;
+      properties = new Properties.Task(getChangeData(), definition, parentProperties);
     }
 
     public List<Node> getSubNodes() throws OrmException {
@@ -214,7 +211,7 @@
         if (tasksFactory != null) {
           NamesFactory namesFactory = task.config.getNamesFactory(tasksFactory.namesFactory);
           if (namesFactory != null && namesFactory.type != null) {
-            new Properties(namesFactory, task.properties);
+            new Properties.NamesFactory(namesFactory, getProperties());
             switch (NamesFactoryType.getNamesFactoryType(namesFactory.type)) {
               case STATIC:
                 addStaticTypeTasksDefinitions(tasksFactory, namesFactory);
@@ -269,6 +266,11 @@
           .getTasks();
     }
 
+    @Override
+    protected Properties.Task getProperties() {
+      return properties;
+    }
+
     protected String resolveTaskFileName(String file) throws ConfigInvalidException {
       if (file == null) {
         throw new ConfigInvalidException("External file not defined");