diff --git a/lib/Minilisp.pm b/lib/Minilisp.pm
index 7ac8b65..d12d968 100644
--- a/lib/Minilisp.pm
+++ b/lib/Minilisp.pm
@@ -362,7 +362,12 @@ sub macro_defun {
 
   return sub {
     my $ctx = shift;
-    my $fn = $body->($ctx);
+    my $fn;
+    my $self = sub {
+      return $fn->(@_);
+    };
+    $ctx->{$ident->{value}} = $self;
+    $fn = $body->($ctx);
     $ctx->{$ident->{value}} = $fn;
     return $fn;
   }