diff --git a/modules/javafx.controls/src/main/java/javafx/scene/control/TreeTableView.java b/modules/javafx.controls/src/main/java/javafx/scene/control/TreeTableView.java
index 89d532faa0..cacb6c7c70 100644
--- a/modules/javafx.controls/src/main/java/javafx/scene/control/TreeTableView.java
+++ b/modules/javafx.controls/src/main/java/javafx/scene/control/TreeTableView.java
@@ -582,11 +582,13 @@ public static int getNodeLevel(TreeItem<?> node) {
         @Override public Boolean call(TreeTableView table) {
             try {
                 TreeItem rootItem = table.getRoot();
-                if (rootItem == null || rootItem.getChildren().isEmpty()) return false;
+                if (rootItem == null) return false;
 
                 TreeSortMode sortMode = table.getSortMode();
                 if (sortMode == null) return false;
 
+                if (rootItem.getChildren().isEmpty()) return true;
+
                 rootItem.lastSortMode = sortMode;
                 rootItem.lastComparator = table.getComparator();
                 rootItem.sort();
diff --git a/modules/javafx.controls/src/test/java/test/javafx/scene/control/TreeTableViewTest.java b/modules/javafx.controls/src/test/java/test/javafx/scene/control/TreeTableViewTest.java
index 9b6d7f9bc0..159e0d2a11 100644
--- a/modules/javafx.controls/src/test/java/test/javafx/scene/control/TreeTableViewTest.java
+++ b/modules/javafx.controls/src/test/java/test/javafx/scene/control/TreeTableViewTest.java
@@ -786,6 +786,18 @@ private void verifySelectionAfterPermutation() {
         });
     }
 
+    @Test public void testSetSortOrderRetainsWhenRootHasNoChildren() {
+        TreeTableView<String> ttv = new TreeTableView<>();
+        TreeItem<String> root = new TreeItem<>("root");
+        root.setExpanded(true);
+        ttv.setRoot(root);
+        assertEquals(0, ttv.getSortOrder().size());
+
+        TreeTableColumn<String, String> ttc = new TreeTableColumn<>("Column");
+        ttv.getSortOrder().add(ttc);
+        assertEquals(1, ttv.getSortOrder().size());
+    }
+
     @Test public void testNPEWhenRootItemIsNull() {
         TreeTableView<String> ttv = new TreeTableView<>();
         ControlTestUtils.runWithExceptionHandler(() -> {