diff --git a/src/main/java/it/inaf/oats/vospace/datamodel/Views.java b/src/main/java/it/inaf/oats/vospace/datamodel/Views.java
index 8c5cc9a0a78fd8d419a012736094d67814c1a16b..452b53a796333c86d7e5c0ed90791ff40e8cb751 100644
--- a/src/main/java/it/inaf/oats/vospace/datamodel/Views.java
+++ b/src/main/java/it/inaf/oats/vospace/datamodel/Views.java
@@ -11,11 +11,11 @@ public abstract class Views {
     }
 
     // Standard views
-    public static String ANY_VIEW_URI = "ivo://ivoa.net/vospace/core#anyview";
-    public static String DEFAULT_VIEW_URI = "ivo://ivoa.net/vospace/core#defaultview";
-    public static String BINARY_VIEW_URI = "ivo://ivoa.net/vospace/core#binaryview";
+    public static final String ANY_VIEW_URI = "ivo://ivoa.net/vospace/core#anyview";
+    public static final String DEFAULT_VIEW_URI = "ivo://ivoa.net/vospace/core#defaultview";
+    public static final String BINARY_VIEW_URI = "ivo://ivoa.net/vospace/core#binaryview";
 
     // Custom views
-    public static String TAR_VIEW_URI = "ivo://ia2.inaf.it/vospace/views#tar";
-    public static String ZIP_VIEW_URI = "ivo://ia2.inaf.it/vospace/views#zip";
+    public static final String TAR_VIEW_URI = "ivo://ia2.inaf.it/vospace/views#tar";
+    public static final String ZIP_VIEW_URI = "ivo://ia2.inaf.it/vospace/views#zip";
 }