diff --git a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/PlateLayouter.java b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/PlateLayouter.java
index 1c66b155f0ffa2c2d095f60b450f9e987008c872..725ac89b1b947cc26e3285fa8e8f24fa83b04ec7 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/PlateLayouter.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/PlateLayouter.java
@@ -151,8 +151,7 @@ public class PlateLayouter
                         { 0, 0 });
                     config.setAnchor(anchor);
                     // WORKAROUND width isn't properly updated - we set fixed value 
-                    config.setMinWidth(150); 
-                    // config.setCloseable(true);
+                    config.setMinWidth(300); 
                     config.setDismissDelay(10000); // 10s to hide
                     GWTUtils.setToolTip(wellComponent, config);
                 }