diff --git a/draw.js b/draw.js
index ed9fb60..0ecc2e0 100644
--- a/draw.js
+++ b/draw.js
@@ -340,9 +340,9 @@ class Drawing {
             i += 1;
           }
           d.definePoint(name, () => {
-            return (function() {
+            return (function(_) {
               return eval(body);
-            }).call(d);
+            })(d);
           });
         } break;
         case 'circle': 
diff --git a/test.md b/test.md
index 9d494a1..278f5af 100644
--- a/test.md
+++ b/test.md
@@ -10,14 +10,14 @@ caption This is a test
 buttons
 frame 0 0 200 100
 axes 200 100
-point p1 this.oscillatingPoint([20, 20], [80, 20], 3000)
+point p1 _.oscillatingPoint([20, 20], [80, 20], 3000)
 fill cyan
 square p1 1000
 point p2 [100, 30]
 fill red
 circle p2
-point p3 [ this.oscillatingValue(20, 80, 3000), 
-  this.oscillatingValue(20, 80, 3000, Math.PI/2) ]
+point p3 [ _.oscillatingValue(20, 80, 3000), 
+  _.oscillatingValue(20, 80, 3000, Math.PI/2) ]
 fill green
 circle p3 1000
 start