diff --git a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/LogicalImageSeriesViewer.java b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/LogicalImageSeriesViewer.java
index abc841bf2c5fc0e776c70ebd6437b518372f4baf..8d22b8979d2c3899658a8a0370eacc94814575ce 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/LogicalImageSeriesViewer.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/LogicalImageSeriesViewer.java
@@ -205,6 +205,7 @@ class LogicalImageSeriesViewer
         return slider;
     }
 
+    //private
     static class ImageSeriesPoint implements Comparable<ImageSeriesPoint>
     {
         private final Float tOrNull, zOrNull;
@@ -323,6 +324,7 @@ class LogicalImageSeriesViewer
         }
     }
 
+    //private
     static class LogicalImageSeriesViewerModel
     {
         private final List<ImageSeriesPoint> sortedPoints;