diff --git a/server-screening/sourceTest/java/ch/systemsx/cisd/openbis/plugin/screening/server/LibraryRegistrationTaskTest.java b/server-screening/sourceTest/java/ch/systemsx/cisd/openbis/plugin/screening/server/LibraryRegistrationTaskTest.java
index eba4189453d888eed8552a00ea31068feadc651d..502a6c353e3940faa473f5c89e05857c37089365 100644
--- a/server-screening/sourceTest/java/ch/systemsx/cisd/openbis/plugin/screening/server/LibraryRegistrationTaskTest.java
+++ b/server-screening/sourceTest/java/ch/systemsx/cisd/openbis/plugin/screening/server/LibraryRegistrationTaskTest.java
@@ -183,6 +183,6 @@ public class LibraryRegistrationTaskTest extends AssertJUnit
         IEntityProperty property =
                 EntityHelper.tryFindProperty(newMaterial.getProperties(),
                         ScreeningConstants.GENE_SYMBOLS);
-        return property.getValue();
+        return property.getStringValue();
     }
 }