diff --git a/Userland/Libraries/LibWeb/DOM/Comment.h b/Userland/Libraries/LibWeb/DOM/Comment.h
index 14424adb46..7f34f43a13 100644
--- a/Userland/Libraries/LibWeb/DOM/Comment.h
+++ b/Userland/Libraries/LibWeb/DOM/Comment.h
@@ -23,4 +23,7 @@ public:
     static NonnullRefPtr<Comment> create_with_global_object(Bindings::WindowObject& window, String const& data);
 };
 
+template<>
+inline bool Node::fast_is<Comment>() const { return is_comment(); }
+
 }
diff --git a/Userland/Libraries/LibWeb/DOM/DocumentFragment.h b/Userland/Libraries/LibWeb/DOM/DocumentFragment.h
index c418194f20..715e9c8bbf 100644
--- a/Userland/Libraries/LibWeb/DOM/DocumentFragment.h
+++ b/Userland/Libraries/LibWeb/DOM/DocumentFragment.h
@@ -36,4 +36,7 @@ private:
     WeakPtr<Element> m_host;
 };
 
+template<>
+inline bool Node::fast_is<DocumentFragment>() const { return is_document_fragment(); }
+
 }
diff --git a/Userland/Libraries/LibWeb/DOM/DocumentType.h b/Userland/Libraries/LibWeb/DOM/DocumentType.h
index d5977a0208..0e8a9eedd0 100644
--- a/Userland/Libraries/LibWeb/DOM/DocumentType.h
+++ b/Userland/Libraries/LibWeb/DOM/DocumentType.h
@@ -43,4 +43,7 @@ private:
     String m_system_id;
 };
 
+template<>
+inline bool Node::fast_is<DocumentType>() const { return is_document_type(); }
+
 }
diff --git a/Userland/Libraries/LibWeb/DOM/ProcessingInstruction.h b/Userland/Libraries/LibWeb/DOM/ProcessingInstruction.h
index f7b1849838..087960ca3c 100644
--- a/Userland/Libraries/LibWeb/DOM/ProcessingInstruction.h
+++ b/Userland/Libraries/LibWeb/DOM/ProcessingInstruction.h
@@ -26,4 +26,7 @@ private:
     String m_target;
 };
 
+template<>
+inline bool Node::fast_is<ProcessingInstruction>() const { return node_type() == (u16)NodeType::PROCESSING_INSTRUCTION_NODE; }
+
 }
diff --git a/Userland/Libraries/LibWeb/DOM/Text.h b/Userland/Libraries/LibWeb/DOM/Text.h
index 8c7e9f38a9..2d839cb63a 100644
--- a/Userland/Libraries/LibWeb/DOM/Text.h
+++ b/Userland/Libraries/LibWeb/DOM/Text.h
@@ -38,4 +38,7 @@ private:
     bool m_always_editable { false };
 };
 
+template<>
+inline bool Node::fast_is<Text>() const { return is_text(); }
+
 }