diff --git a/common/source/java/ch/systemsx/cisd/common/Constants.java b/common/source/java/ch/systemsx/cisd/common/Constants.java
index 5b19c4bd0635f9e88aea8738d60db7e76e0cda38..b100035b0b4ea9832198d4930b0bbc5a43c5ab06 100644
--- a/common/source/java/ch/systemsx/cisd/common/Constants.java
+++ b/common/source/java/ch/systemsx/cisd/common/Constants.java
@@ -23,9 +23,14 @@ import org.apache.commons.lang.time.DateUtils;
  * 
  * @author Bernd Rinn
  */
-public class Constants
+public final class Constants
 {
 
+    private Constants()
+    {
+        // This class can not be instantiated.
+    }
+
     /** String that indicates a marker file */
     public static final String MARKER_PREFIX = ".MARKER_";