diff --git a/libraries/p5.gui.js b/libraries/p5.gui.js
index c758c2c..1a2efaf 100644
--- a/libraries/p5.gui.js
+++ b/libraries/p5.gui.js
@@ -165,6 +165,10 @@
         var val = object[arg];
         var typ = typeof val;
 
+        if(typeof arg === 'function') {
+          typ = typeof arg
+        }
+
         //console.log(typ, arg, val);
 
         // don't need to show the sliders for range min, max and step of a property
@@ -227,6 +231,10 @@
             this.bindBoolean(arg, object[arg], object);
             break;
 
+          case 'function':
+            this.addButton(arg.name, arg);
+            break;
+
         }
       }
     };