diff --git a/render.js b/render.js
index 5db9dcb..efb0e87 100644
--- a/render.js
+++ b/render.js
@@ -348,7 +348,11 @@
     }
   };
   agg_funcs.count.return_type = T_NUM;
+  agg_funcs.count_nz.return_type = T_NUM;
+  agg_funcs.count_distinct.return_type = T_NUM;
   agg_funcs.sum.return_type = T_NUM;
+  agg_funcs.cat.return_type = T_STRING;
+  agg_funcs.color.return_type = T_NUM;
 
 
   function groupBy(ingrid, keys, values) {