diff --git a/screening/source/java/ch/systemsx/cisd/openbis/dss/etl/ImageSizeFeedingMaintenanceTask.java b/screening/source/java/ch/systemsx/cisd/openbis/dss/etl/ImageSizeFeedingMaintenanceTask.java
index 559995f4bd0ac0420f37d5b8563ecb8899db1746..f46add687890b275967fd3e0e336f2eff8cc66ed 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/dss/etl/ImageSizeFeedingMaintenanceTask.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/dss/etl/ImageSizeFeedingMaintenanceTask.java
@@ -186,15 +186,8 @@ public class ImageSizeFeedingMaintenanceTask implements IDataStoreLockingMainten
         BufferedImage unchangedImage = image.getUnchangedImage();
         int width = unchangedImage.getWidth();
         int height = unchangedImage.getHeight();
-        String fileType = null;
-        String uniqueId = image.getUniqueId();
-        int lastIndexOfDot = uniqueId.lastIndexOf('.');
-        if (lastIndexOfDot >= 0)
-        {
-            fileType = uniqueId.substring(lastIndexOfDot + 1);
-        }
         dao.addImageZoomLevel(new ImgImageZoomLevelDTO(dataSetCode, original, "", width, height,
-                null, fileType, dataSetId));
+                null, null, dataSetId));
         return (original ? "Original" : "Thumbnail") + " size " + width + "x" + height
                 + " added for data set " + dataSetCode;
     }
diff --git a/screening/sourceTest/java/ch/systemsx/cisd/openbis/dss/etl/ImageSizeFeedingMaintenanceTaskTest.java b/screening/sourceTest/java/ch/systemsx/cisd/openbis/dss/etl/ImageSizeFeedingMaintenanceTaskTest.java
index 8ba05b0416c7d76cc2bdc58a409c41db91068d97..ed3a1849eef9ff1cf3eae4b5196e6be17223f61e 100644
--- a/screening/sourceTest/java/ch/systemsx/cisd/openbis/dss/etl/ImageSizeFeedingMaintenanceTaskTest.java
+++ b/screening/sourceTest/java/ch/systemsx/cisd/openbis/dss/etl/ImageSizeFeedingMaintenanceTaskTest.java
@@ -57,7 +57,7 @@ public class ImageSizeFeedingMaintenanceTaskTest extends AssertJUnit
 
         public MockAbsoluteImageReference(int width, int height)
         {
-            super(null, "img.jpg", null, null, new RequestedImageSize(null, false), null,
+            super(null, null, null, null, new RequestedImageSize(null, false), null,
                     new ImageTransfomationFactories(), null);
             this.width = width;
             this.height = height;
@@ -193,9 +193,9 @@ public class ImageSizeFeedingMaintenanceTaskTest extends AssertJUnit
                 + "1 original image sizes and 1 thumbnail image sizes are added to the database.",
                 logRecorder.getLogContent());
         assertEquals("[ImgImageZoomLevelDTO{physicalDatasetPermId=ds2,isOriginal=true,"
-                + "containerDatasetId=99715,rootPath=,width=144,height=89,colorDepth=<null>,fileType=jpg,id=0}, "
+                + "containerDatasetId=99715,rootPath=,width=144,height=89,colorDepth=<null>,fileType=<null>,id=0}, "
                 + "ImgImageZoomLevelDTO{physicalDatasetPermId=ds3,isOriginal=false,"
-                + "containerDatasetId=99716,rootPath=,width=21,height=34,colorDepth=<null>,fileType=jpg,id=0}]",
+                + "containerDatasetId=99716,rootPath=,width=21,height=34,colorDepth=<null>,fileType=<null>,id=0}]",
                 zoomLevels.toString());
         context.assertIsSatisfied();
     }
@@ -233,7 +233,7 @@ public class ImageSizeFeedingMaintenanceTaskTest extends AssertJUnit
         		"0 original image sizes and 0 thumbnail image sizes are added to the database.",
                 logRecorder.getLogContent());
         assertEquals("[ImgImageZoomLevelDTO{physicalDatasetPermId=ds2,isOriginal=true,"
-                + "containerDatasetId=99715,rootPath=,width=1,height=2,colorDepth=<null>,fileType=jpg,id=0}]",
+                + "containerDatasetId=99715,rootPath=,width=1,height=2,colorDepth=<null>,fileType=<null>,id=0}]",
                 zoomLevels.toString());
         context.assertIsSatisfied();
     }