diff --git a/lib/cartodb/api/overviews_api.js b/lib/cartodb/api/overviews_api.js
index 9b6dc1c6..81d279b1 100644
--- a/lib/cartodb/api/overviews_api.js
+++ b/lib/cartodb/api/overviews_api.js
@@ -33,12 +33,14 @@ OverviewsApi.prototype.getOverviewsMetadata = function (username, sql, callback)
                             done(new Error('could not get overviews metadata: ' + msg));
                             return;
                         }
-                        var table_metadata = {};
-                        for ( var i=0; i<rows.length; ++i ) {
-                          var row = rows[i];
-                          table_metadata[row.z] = { table: row.overview_table };
+                        if ( rows.length > 0 ) {
+                          var table_metadata = {};
+                          for ( var i=0; i<rows.length; ++i ) {
+                            var row = rows[i];
+                            table_metadata[row.z] = { table: row.overview_table };
+                          }
+                          metadata[tableName] = table_metadata;
                         }
-                        metadata[tableName] = table_metadata;
                         done(null);
                     });
                 });