diff --git a/environment.go b/environment.go
index 0d6d2ea..a06aa6d 100644
--- a/environment.go
+++ b/environment.go
@@ -36,9 +36,9 @@ func (env *Environment) Get(name string, exp *Expr) interface{} {
 
 func (env *Environment) Set(name string, value interface{}, exp *Expr) interface{} {
 	scope := env.Lookup(name)
-	if scope == nil && env.parent != nil {
-		Error(exp, "Undefined variable '%s'", name)
-	}
+	// if scope == nil && env.parent != nil {
+	// 	Error(exp, "Undefined variable '%s'", name)
+	// }
 	if scope != nil {
 		scope.vars[name] = value
 	} else {
diff --git a/example/test.rune b/example/test.rune
index a4d86af..9da154e 100644
--- a/example/test.rune
+++ b/example/test.rune
@@ -1,3 +1,14 @@
+foo = "bar"
+exit()
+
+testFun = fun() {
+    foo = "bar"
+    println(foo)
+}
+
+testFun()
+
+exit()
 fibonacci = fun(n) {
     if n <= 0 then return = 0
     elif n == 1 then return = 1