diff --git a/src/Extension/SandboxExtension.php b/src/Extension/SandboxExtension.php
index 7f9f7ed35..09ea286e7 100644
--- a/src/Extension/SandboxExtension.php
+++ b/src/Extension/SandboxExtension.php
@@ -90,7 +90,7 @@ final class SandboxExtension extends AbstractExtension
 
     public function ensureToStringAllowed($obj)
     {
-        if ($this->isSandboxed() && \is_object($obj)) {
+        if ($this->isSandboxed() && \is_object($obj) && method_exists($obj, '__toString')) {
             $this->policy->checkMethodAllowed($obj, '__toString');
         }
 
diff --git a/src/Node/CheckSecurityNode.php b/src/Node/CheckSecurityNode.php
index d9bdcfd49..59857ca5a 100644
--- a/src/Node/CheckSecurityNode.php
+++ b/src/Node/CheckSecurityNode.php
@@ -45,12 +45,13 @@ class CheckSecurityNode extends Node
         }
 
         $compiler
+            ->write("\$this->sandbox = \$this->env->getExtension('\Twig\Extension\SandboxExtension');\n")
             ->write('$tags = ')->repr(array_filter($tags))->raw(";\n")
             ->write('$filters = ')->repr(array_filter($filters))->raw(";\n")
             ->write('$functions = ')->repr(array_filter($functions))->raw(";\n\n")
             ->write("try {\n")
             ->indent()
-            ->write("\$this->extensions[SandboxExtension::class]->checkSecurity(\n")
+            ->write("\$this->sandbox->checkSecurity(\n")
             ->indent()
             ->write(!$tags ? "[],\n" : "['".implode("', '", array_keys($tags))."'],\n")
             ->write(!$filters ? "[],\n" : "['".implode("', '", array_keys($filters))."'],\n")
diff --git a/src/Node/ModuleNode.php b/src/Node/ModuleNode.php
index 5e11761fc..d68b639d5 100644
--- a/src/Node/ModuleNode.php
+++ b/src/Node/ModuleNode.php
@@ -317,8 +317,8 @@ class ModuleNode extends Node
         }
 
         $compiler
-            ->outdent()
             ->subcompile($this->getNode('constructor_end'))
+            ->outdent()
             ->write("}\n\n")
         ;
     }
diff --git a/src/Node/SandboxNode.php b/src/Node/SandboxNode.php
index 9889d65cf..4697bd45e 100644
--- a/src/Node/SandboxNode.php
+++ b/src/Node/SandboxNode.php
@@ -29,16 +29,15 @@ class SandboxNode extends Node
     {
         $compiler
             ->addDebugInfo($this)
-            ->write("\$sandbox = \$this->extensions[SandboxExtension::class];\n")
-            ->write("if (!\$alreadySandboxed = \$sandbox->isSandboxed()) {\n")
+            ->write("if (!\$alreadySandboxed = \$this->sandbox->isSandboxed()) {\n")
             ->indent()
-            ->write("\$sandbox->enableSandbox();\n")
+            ->write("\$this->sandbox->enableSandbox();\n")
             ->outdent()
             ->write("}\n")
             ->subcompile($this->getNode('body'))
             ->write("if (!\$alreadySandboxed) {\n")
             ->indent()
-            ->write("\$sandbox->disableSandbox();\n")
+            ->write("\$this->sandbox->disableSandbox();\n")
             ->outdent()
             ->write("}\n")
         ;
diff --git a/src/NodeVisitor/SandboxNodeVisitor.php b/src/NodeVisitor/SandboxNodeVisitor.php
index 44ac946b5..507206db5 100644
--- a/src/NodeVisitor/SandboxNodeVisitor.php
+++ b/src/NodeVisitor/SandboxNodeVisitor.php
@@ -75,7 +75,7 @@ final class SandboxNodeVisitor extends AbstractNodeVisitor
         if ($node instanceof ModuleNode) {
             $this->inAModule = false;
 
-            $node->setNode('display_start', new Node([new CheckSecurityNode($this->filters, $this->tags, $this->functions), $node->getNode('display_start')]));
+            $node->setNode('constructor_end', new Node([new CheckSecurityNode($this->filters, $this->tags, $this->functions), $node->getNode('display_start')]));
         }
 
         return $node;
diff --git a/src/Template.php b/src/Template.php
index e6740e21d..669d36054 100644
--- a/src/Template.php
+++ b/src/Template.php
@@ -39,6 +39,7 @@ abstract class Template
     protected $blocks = [];
     protected $traits = [];
     protected $extensions = [];
+    protected $sandbox;
 
     public function __construct(Environment $env)
     {
diff --git a/test/Twig/Tests/Node/SandboxTest.php b/test/Twig/Tests/Node/SandboxTest.php
index 85bba0d15..7dd3e08f0 100644
--- a/test/Twig/Tests/Node/SandboxTest.php
+++ b/test/Twig/Tests/Node/SandboxTest.php
@@ -32,13 +32,12 @@ class Twig_Tests_Node_SandboxTest extends NodeTestCase
 
         $tests[] = [$node, <<<EOF
 // line 1
-\$sandbox = \$this->extensions[SandboxExtension::class];
-if (!\$alreadySandboxed = \$sandbox->isSandboxed()) {
-    \$sandbox->enableSandbox();
+if (!\$alreadySandboxed = \$this->sandbox->isSandboxed()) {
+    \$this->sandbox->enableSandbox();
 }
 echo "foo";
 if (!\$alreadySandboxed) {
-    \$sandbox->disableSandbox();
+    \$this->sandbox->disableSandbox();
 }
 EOF
         ];
diff --git a/test/Twig/Tests/Node/SandboxedPrintTest.php b/test/Twig/Tests/Node/SandboxedPrintTest.php
index 18f7d11f6..df7b35cf5 100644
--- a/test/Twig/Tests/Node/SandboxedPrintTest.php
+++ b/test/Twig/Tests/Node/SandboxedPrintTest.php
@@ -9,12 +9,9 @@
  * file that was distributed with this source code.
  */
 
-use Twig\Node\Expression\ArrayExpression;
 use Twig\Node\Expression\ConstantExpression;
-use Twig\Node\Expression\GetAttrExpression;
 use Twig\Node\Expression\NameExpression;
 use Twig\Node\SandboxedPrintNode;
-use Twig\Template;
 use Twig\Test\NodeTestCase;
 
 class Twig_Tests_Node_SandboxedPrintTest extends NodeTestCase