diff --git a/data-discovery/src/main/java/webapi/formatfilter/ObscoreExt.java b/data-discovery/src/main/java/webapi/formatfilter/ObscoreExt.java
index cec53fc688812177038453512e2e21674497f28b..1ae4ab02bb810134bca7a37da2b1f4769ca04b83 100644
--- a/data-discovery/src/main/java/webapi/formatfilter/ObscoreExt.java
+++ b/data-discovery/src/main/java/webapi/formatfilter/ObscoreExt.java
@@ -43,7 +43,7 @@ class ObscoreExt
 
       new ColumnInfo( "access_url",     String.class, "Access URL" ),
       new ColumnInfo( "access_format",  String.class, "Format (MIME type)" ),
-      new ColumnInfo( "access_estsize", Long.class,   "Extimated size (KB)" ),
+      genLongWithNullColInfo("access_estsize", "Extimated size (KB)" ),
 
       new ColumnInfo( "target_name", String.class,  "Target" ),