--- a/src/ast_scope.rs
+++ b/src/ast_scope.rs
@@ -3,8 +3,14 @@ use python_ast::{Module, Statement, Expr
 use std::collections::HashMap;
 
 #[derive(Debug)]
+struct BlockStatement {
+    statement: Statement,
+    block: Option<Block>
+}
+
+#[derive(Debug)]
 struct Block {
-    statements: Vec<(Statement, Option<Box<Block>>)>,
+    statements: Vec<BlockStatement>,
     bindings: Vec<String>
 }
 
@@ -35,7 +41,7 @@ fn scope_statement(statement: Statement,
             for statement in statements {
                 scope_statement(statement, &mut function_block);
             }
-            Some(Box::new(function_block))
+            Some(function_block)
         },
         Statement::ImportFrom(module, names) => {
             for name in names {
@@ -54,7 +60,7 @@ fn scope_statement(statement: Statement,
         },
         _ => None
     };
-    block.statements.push((statement, new_block));
+    block.statements.push(BlockStatement{statement: statement, block: new_block});
 }
 
 #[allow(dead_code)]