diff --git a/Userland/Libraries/LibWeb/DOM/AbstractRange.cpp b/Userland/Libraries/LibWeb/DOM/AbstractRange.cpp
index 8a32a55974..9a99a7cc62 100644
--- a/Userland/Libraries/LibWeb/DOM/AbstractRange.cpp
+++ b/Userland/Libraries/LibWeb/DOM/AbstractRange.cpp
@@ -10,7 +10,7 @@
 
 namespace Web::DOM {
 
-AbstractRange::AbstractRange(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset)
+AbstractRange::AbstractRange(Node& start_container, WebIDL::UnsignedLong start_offset, Node& end_container, WebIDL::UnsignedLong end_offset)
     : Bindings::PlatformObject(start_container.realm())
     , m_start_container(start_container)
     , m_start_offset(start_offset)
diff --git a/Userland/Libraries/LibWeb/DOM/AbstractRange.h b/Userland/Libraries/LibWeb/DOM/AbstractRange.h
index af8b04bad3..054c83bec2 100644
--- a/Userland/Libraries/LibWeb/DOM/AbstractRange.h
+++ b/Userland/Libraries/LibWeb/DOM/AbstractRange.h
@@ -9,9 +9,11 @@
 
 #include <LibWeb/Bindings/PlatformObject.h>
 #include <LibWeb/Forward.h>
+#include <LibWeb/WebIDL/Types.h>
 
 namespace Web::DOM {
 
+// https://dom.spec.whatwg.org/#abstractrange
 class AbstractRange : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(AbstractRange, Bindings::PlatformObject);
 
@@ -20,11 +22,11 @@ public:
 
     Node* start_container() { return m_start_container.ptr(); }
     Node const* start_container() const { return m_start_container.ptr(); }
-    unsigned start_offset() const { return m_start_offset; }
+    WebIDL::UnsignedLong start_offset() const { return m_start_offset; }
 
     Node* end_container() { return m_end_container.ptr(); }
     Node const* end_container() const { return m_end_container.ptr(); }
-    unsigned end_offset() const { return m_end_offset; }
+    WebIDL::UnsignedLong end_offset() const { return m_end_offset; }
 
     // https://dom.spec.whatwg.org/#range-collapsed
     bool collapsed() const
@@ -34,16 +36,16 @@ public:
     }
 
 protected:
-    AbstractRange(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset);
+    AbstractRange(Node& start_container, WebIDL::UnsignedLong start_offset, Node& end_container, WebIDL::UnsignedLong end_offset);
 
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
 
     JS::NonnullGCPtr<Node> m_start_container;
-    u32 m_start_offset;
+    WebIDL::UnsignedLong m_start_offset;
 
     JS::NonnullGCPtr<Node> m_end_container;
-    u32 m_end_offset;
+    WebIDL::UnsignedLong m_end_offset;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/DOM/Range.cpp b/Userland/Libraries/LibWeb/DOM/Range.cpp
index 1a35748bf2..ff1778e36f 100644
--- a/Userland/Libraries/LibWeb/DOM/Range.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Range.cpp
@@ -44,7 +44,7 @@ JS::NonnullGCPtr<Range> Range::create(Document& document)
     return realm.heap().allocate<Range>(realm, document);
 }
 
-JS::NonnullGCPtr<Range> Range::create(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset)
+JS::NonnullGCPtr<Range> Range::create(Node& start_container, WebIDL::UnsignedLong start_offset, Node& end_container, WebIDL::UnsignedLong end_offset)
 {
     auto& realm = start_container.realm();
     return realm.heap().allocate<Range>(realm, start_container, start_offset, end_container, end_offset);
@@ -61,7 +61,7 @@ Range::Range(Document& document)
 {
 }
 
-Range::Range(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset)
+Range::Range(Node& start_container, WebIDL::UnsignedLong start_offset, Node& end_container, WebIDL::UnsignedLong end_offset)
     : AbstractRange(start_container, start_offset, end_container, end_offset)
 {
     live_ranges().set(this);
@@ -207,13 +207,13 @@ WebIDL::ExceptionOr<void> Range::set_start_or_end(Node& node, u32 offset, StartO
 }
 
 // https://dom.spec.whatwg.org/#concept-range-bp-set
-WebIDL::ExceptionOr<void> Range::set_start(Node& node, u32 offset)
+WebIDL::ExceptionOr<void> Range::set_start(Node& node, WebIDL::UnsignedLong offset)
 {
     // The setStart(node, offset) method steps are to set the start of this to boundary point (node, offset).
     return set_start_or_end(node, offset, StartOrEnd::Start);
 }
 
-WebIDL::ExceptionOr<void> Range::set_end(Node& node, u32 offset)
+WebIDL::ExceptionOr<void> Range::set_end(Node& node, WebIDL::UnsignedLong offset)
 {
     // The setEnd(node, offset) method steps are to set the end of this to boundary point (node, offset).
     return set_start_or_end(node, offset, StartOrEnd::End);
@@ -276,7 +276,7 @@ WebIDL::ExceptionOr<void> Range::set_end_after(Node& node)
 }
 
 // https://dom.spec.whatwg.org/#dom-range-compareboundarypoints
-WebIDL::ExceptionOr<i16> Range::compare_boundary_points(u16 how, Range const& source_range) const
+WebIDL::ExceptionOr<WebIDL::Short> Range::compare_boundary_points(WebIDL::UnsignedShort how, Range const& source_range) const
 {
     // 1. If how is not one of
     //      - START_TO_START,
@@ -499,7 +499,7 @@ bool Range::intersects_node(Node const& node) const
 }
 
 // https://dom.spec.whatwg.org/#dom-range-ispointinrange
-WebIDL::ExceptionOr<bool> Range::is_point_in_range(Node const& node, u32 offset) const
+WebIDL::ExceptionOr<bool> Range::is_point_in_range(Node const& node, WebIDL::UnsignedLong offset) const
 {
     // 1. If node’s root is different from this’s root, return false.
     if (&node.root() != &root())
@@ -524,7 +524,7 @@ WebIDL::ExceptionOr<bool> Range::is_point_in_range(Node const& node, u32 offset)
 }
 
 // https://dom.spec.whatwg.org/#dom-range-comparepoint
-WebIDL::ExceptionOr<i16> Range::compare_point(Node const& node, u32 offset) const
+WebIDL::ExceptionOr<WebIDL::Short> Range::compare_point(Node const& node, WebIDL::UnsignedLong offset) const
 {
     // 1. If node’s root is different from this’s root, then throw a "WrongDocumentError" DOMException.
     if (&node.root() != &root())
diff --git a/Userland/Libraries/LibWeb/DOM/Range.h b/Userland/Libraries/LibWeb/DOM/Range.h
index 146c08a5a7..57f7a2cd83 100644
--- a/Userland/Libraries/LibWeb/DOM/Range.h
+++ b/Userland/Libraries/LibWeb/DOM/Range.h
@@ -10,6 +10,7 @@
 
 #include <LibWeb/DOM/AbstractRange.h>
 #include <LibWeb/Selection/Selection.h>
+#include <LibWeb/WebIDL/Types.h>
 
 namespace Web::DOM {
 
@@ -29,15 +30,15 @@ class Range final : public AbstractRange {
 public:
     [[nodiscard]] static JS::NonnullGCPtr<Range> create(Document&);
     [[nodiscard]] static JS::NonnullGCPtr<Range> create(HTML::Window&);
-    [[nodiscard]] static JS::NonnullGCPtr<Range> create(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset);
+    [[nodiscard]] static JS::NonnullGCPtr<Range> create(Node& start_container, WebIDL::UnsignedLong start_offset, Node& end_container, WebIDL::UnsignedLong end_offset);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Range>> construct_impl(JS::Realm&);
 
     virtual ~Range() override;
 
     // FIXME: There are a ton of methods missing here.
 
-    WebIDL::ExceptionOr<void> set_start(Node& node, u32 offset);
-    WebIDL::ExceptionOr<void> set_end(Node& node, u32 offset);
+    WebIDL::ExceptionOr<void> set_start(Node& node, WebIDL::UnsignedLong offset);
+    WebIDL::ExceptionOr<void> set_end(Node& node, WebIDL::UnsignedLong offset);
     WebIDL::ExceptionOr<void> set_start_before(Node& node);
     WebIDL::ExceptionOr<void> set_start_after(Node& node);
     WebIDL::ExceptionOr<void> set_end_before(Node& node);
@@ -47,14 +48,14 @@ public:
     WebIDL::ExceptionOr<void> select_node_contents(Node&);
 
     // https://dom.spec.whatwg.org/#dom-range-start_to_start
-    enum HowToCompareBoundaryPoints : u16 {
+    enum HowToCompareBoundaryPoints : WebIDL::UnsignedShort {
         START_TO_START = 0,
         START_TO_END = 1,
         END_TO_END = 2,
         END_TO_START = 3,
     };
 
-    WebIDL::ExceptionOr<i16> compare_boundary_points(u16 how, Range const& source_range) const;
+    WebIDL::ExceptionOr<WebIDL::Short> compare_boundary_points(WebIDL::UnsignedShort how, Range const& source_range) const;
 
     JS::NonnullGCPtr<Range> inverted() const;
     JS::NonnullGCPtr<Range> normalized() const;
@@ -70,8 +71,8 @@ public:
     }
 
     bool intersects_node(Node const&) const;
-    WebIDL::ExceptionOr<bool> is_point_in_range(Node const&, u32 offset) const;
-    WebIDL::ExceptionOr<i16> compare_point(Node const&, u32 offset) const;
+    WebIDL::ExceptionOr<bool> is_point_in_range(Node const&, WebIDL::UnsignedLong offset) const;
+    WebIDL::ExceptionOr<WebIDL::Short> compare_point(Node const&, WebIDL::UnsignedLong offset) const;
 
     WebIDL::ExceptionOr<void> delete_contents();
     WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> extract_contents();
@@ -94,7 +95,7 @@ public:
 
 private:
     explicit Range(Document&);
-    Range(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset);
+    Range(Node& start_container, WebIDL::UnsignedLong start_offset, Node& end_container, WebIDL::UnsignedLong end_offset);
 
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;