diff --git a/lib/DOM.php b/lib/DOM.php
index caa0db6..725c8c9 100644
--- a/lib/DOM.php
+++ b/lib/DOM.php
@@ -9,7 +9,8 @@ class DOM {
     // Instance used to pass around the implementation and the document. PHP's DOM
     // cannot append a DOCTYPE to a DOMDocument, so the document must be created
     // when the DOCTYPE is. This creates a problem where the Parser sometimes needs
-    // an implementation before the TreeBuilder is initiated.
+    // an implementation before the TreeBuilder is initiated. This instance is used
+    // to work around that problem.
     public function __construct($document = null) {
         if (is_null($document)) {
             $this->implementation = new \DOMImplementation();
diff --git a/lib/Parser.php b/lib/Parser.php
index 1213d5d..4deee2c 100644
--- a/lib/Parser.php
+++ b/lib/Parser.php
@@ -24,6 +24,8 @@ class Parser {
     protected $parseError;
     // The stack of open elements, uses Stack
     protected $stack;
+    // Used to store the template insertion modes
+    protected $templateInsertionModes;
     // Instance of the Tokenizer class used for creating tokens
     protected $tokenizer;
     // Instance of the TreeBuilder class used for building the document
@@ -78,10 +80,14 @@ class Parser {
 
         // Initialize the stack of open elements.
         static::$instance->stack = new OpenElementsStack(static::$instance->fragmentCase, static::$instance->fragmentContext);
+        // Initialize the template insertion modes stack if necessary.
+        if (is_null(static::$instance->templateInsertionModes)) {
+            static::$instance->templateInsertionModes = new Stack();
+        }
         // Initialize the tokenizer.
         static::$instance->tokenizer = new Tokenizer(static::$instance->data, static::$instance->stack);
         // Initialize the tree builder.
-        static::$instance->treeBuilder = new TreeBuilder(static::$instance->DOM, static::$instance->formElement, static::$instance->fragmentCase, static::$instance->fragmentContext, static::$instance->stack, static::$instance->tokenizer);
+        static::$instance->treeBuilder = new TreeBuilder(static::$instance->DOM, static::$instance->formElement, static::$instance->fragmentCase, static::$instance->fragmentContext, static::$instance->stack, static::$instance->templateInsertionModes, static::$instance->tokenizer);
         // Initialize the parse error handler.
         static::$instance->parseError = new ParseError(static::$instance->data);
 
@@ -151,7 +157,10 @@ class Parser {
         # If the context element is a template element, push "in template" onto the
         # stack of template insertion modes so that it is the new current template
         # insertion mode.
-        // DEVIATION: No scripting.
+        if ($context instanceof \DOMelement && $context->nodeName === 'template') {
+            static::$templateInsertionModes = new Stack();
+            static::$templateInsertionModes[] = TreeBuilder::IN_TEMPLATE_MODE;
+        }
 
         # Reset the parser's insertion mode appropriately.
         // DEVIATION: The insertion mode will be always 'in body', not 'before head' if
diff --git a/lib/Stack.php b/lib/Stack.php
index 2c8c598..0443956 100644
--- a/lib/Stack.php
+++ b/lib/Stack.php
@@ -2,7 +2,7 @@
 declare(strict_types=1);
 namespace dW\HTML5;
 
-abstract class Stack implements \ArrayAccess {
+class Stack implements \ArrayAccess {
     protected $_storage = [];
     protected $fragmentCase;
     protected $fragmentContext;
diff --git a/lib/TreeBuilder.php b/lib/TreeBuilder.php
index 76ded6c..c5db58f 100644
--- a/lib/TreeBuilder.php
+++ b/lib/TreeBuilder.php
@@ -36,6 +36,8 @@ class TreeBuilder {
     protected $tokenizer;
     // Used to check if the document is in quirks mode
     protected $quirksMode;
+    // Used to store the template insertion modes
+    protected $templateInsertionModes;
 
 
     // Instance used with the static token insertion methods.
@@ -73,7 +75,7 @@ class TreeBuilder {
     const QUIRKS_MODE_LIMITED = 2;
 
 
-    public function __construct(DOM $dom, $formElement, bool $fragmentCase = false, $fragmentContext = null, OpenElementsStack $stack, Tokenizer $tokenizer) {
+    public function __construct(DOM $dom, $formElement, bool $fragmentCase = false, $fragmentContext = null, OpenElementsStack $stack, Stack $templateInsertionModes, Tokenizer $tokenizer) {
         // If the form element isn't an instance of DOMElement that has a node name of
         // "form" or null then there's a problem.
         if (!is_null($formElement) && !($formElement instanceof DOMElement && $formElement->nodeName === 'form')) {
@@ -94,6 +96,7 @@ class TreeBuilder {
         $this->fragmentCase = $fragmentCase;
         $this->fragmentContext = $fragmentContext;
         $this->stack = $stack;
+        $this->templateInsertionModes = $templateInsertionModes;
         $this->tokenizer = $tokenizer;
 
         // Initialize the list of active formatting elements.
@@ -641,7 +644,7 @@ class TreeBuilder {
                             $this->insertionMode = self::IN_TEMPLATE_MODE;
                             # Push "in template" onto the stack of template insertion modes so that it is
                             # the new current template insertion mode.
-                            // DEVIATION: No scripting.
+                            $this->templateInsertionModes = self::IN_TEMPLATE_MODE;
                         }
                         # A start tag whose tag name is "head"
                         elseif ($token->name === 'head') {
@@ -710,7 +713,7 @@ class TreeBuilder {
                                 $this->activeFormattingElementsList->clearToTheLastMarker();
 
                                 # 5. Pop the current template insertion mode off the stack of template insertion modes.
-                                // DEVIATION: No scripting.
+                                $this->templateInsertionModes->pop();
 
                                 # 6. Reset the insertion mode appropriately.
                                 $this->resetInsertionMode();