diff --git a/.github/actions/install/action.yml b/.github/actions/install/action.yml
index 69ed6a91..58ff9b11 100644
--- a/.github/actions/install/action.yml
+++ b/.github/actions/install/action.yml
@@ -17,7 +17,7 @@ inputs:
   zig-v8:
     description: 'zig v8 version to install'
     required: false
-    default: 'v0.1.22'
+    default: 'v0.1.23'
   v8:
     description: 'v8 version to install'
     required: false
diff --git a/Dockerfile b/Dockerfile
index 6944a011..70d609d1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,7 +5,7 @@ ARG ZIG=0.14.0
 ARG ZIG_MINISIG=RWSGOq2NVecA2UPNdBUZykf1CCb147pkmdtYxgb3Ti+JO/wCYvhbAb/U
 ARG ARCH=x86_64
 ARG V8=11.1.134
-ARG ZIG_V8=v0.1.22
+ARG ZIG_V8=v0.1.23
 
 RUN apt-get update -yq && \
     apt-get install -yq xz-utils \
diff --git a/build.zig.zon b/build.zig.zon
index 1e8805b5..58f5508f 100644
--- a/build.zig.zon
+++ b/build.zig.zon
@@ -13,8 +13,8 @@
             .hash = "tigerbeetle_io-0.0.0-ViLgxpyRBAB5BMfIcj3KMXfbJzwARs9uSl8aRy2OXULd",
         },
         .v8 = .{
-            .url = "https://github.com/lightpanda-io/zig-v8-fork/archive/4809111f930293c6d5082971ad7ffc3d822b6f37.tar.gz",
-            .hash = "v8-0.0.0-xddH632xAwAjF7ieh48tjbMpu7fVVGr3r3aLwmBbFvPk",
+            .url = "https://github.com/lightpanda-io/zig-v8-fork/archive/6f1ee74a0e7002ea3568e337ab716c1e75c53769.tar.gz",
+            .hash = "v8-0.0.0-xddH6z2yAwCOPUGmy1IgXysI1yWt8ftd2Z3D5zp0I9tV",
         },
         //.v8 = .{ .path = "../zig-v8-fork" },
         //.tigerbeetle_io = .{ .path = "../tigerbeetle-io" },
diff --git a/src/browser/dom/html_collection.zig b/src/browser/dom/html_collection.zig
index 1291a0aa..7c9286ac 100644
--- a/src/browser/dom/html_collection.zig
+++ b/src/browser/dom/html_collection.zig
@@ -149,17 +149,43 @@ pub fn HTMLCollectionByName(
     };
 }
 
-pub fn HTMLCollectionAll(
-    root: ?*parser.Node,
-    include_root: bool,
-) !HTMLCollection {
-    return HTMLCollection{
-        .root = root,
-        .walker = .{ .walkerDepthFirst = .{} },
-        .matcher = .{ .matchTrue = .{} },
-        .include_root = include_root,
+// HTMLAllCollection is a special type: instances of it are falsy. It's the only
+// object in the WebAPI that behaves like this - in fact, it's even a special
+// case in the JavaScript spec.
+// This is important, because a lot of browser detection rely on this behavior
+// to determine what browser is running.
+
+// It's also possible to use an instance like a function:
+//   document.all(3)
+//   document.all('some_id')
+pub const HTMLAllCollection = struct {
+    pub const prototype = *HTMLCollection;
+
+    proto: HTMLCollection,
+
+    pub const mark_as_undetectable = true;
+
+    pub fn init(root: ?*parser.Node) HTMLAllCollection {
+        return .{ .proto = .{
+            .root = root,
+            .walker = .{ .walkerDepthFirst = .{} },
+            .matcher = .{ .matchTrue = .{} },
+            .include_root = true,
+        } };
+    }
+
+    const CAllAsFunctionArg = union(enum) {
+        index: u32,
+        id: []const u8,
     };
-}
+
+    pub fn jsCallAsFunction(self: *HTMLAllCollection, arg: CAllAsFunctionArg) !?Union {
+        return switch (arg) {
+            .index => |i| self.proto._item(i),
+            .id => |id| self.proto._namedItem(id),
+        };
+    }
+};
 
 pub fn HTMLCollectionChildren(
     root: ?*parser.Node,
diff --git a/src/browser/dom/node.zig b/src/browser/dom/node.zig
index 79e89cf2..7f2747e1 100644
--- a/src/browser/dom/node.zig
+++ b/src/browser/dom/node.zig
@@ -33,6 +33,7 @@ const Document = @import("document.zig").Document;
 const DocumentType = @import("document_type.zig").DocumentType;
 const DocumentFragment = @import("document_fragment.zig").DocumentFragment;
 const HTMLCollection = @import("html_collection.zig").HTMLCollection;
+const HTMLAllCollection = @import("html_collection.zig").HTMLAllCollection;
 const HTMLCollectionIterator = @import("html_collection.zig").HTMLCollectionIterator;
 const Walker = @import("walker.zig").WalkerDepthFirst;
 
@@ -50,6 +51,7 @@ pub const Interfaces = .{
     DocumentType,
     DocumentFragment,
     HTMLCollection,
+    HTMLAllCollection,
     HTMLCollectionIterator,
     HTML.Interfaces,
 };
diff --git a/src/browser/html/document.zig b/src/browser/html/document.zig
index 95619940..89370f50 100644
--- a/src/browser/html/document.zig
+++ b/src/browser/html/document.zig
@@ -151,8 +151,8 @@ pub const HTMLDocument = struct {
         return try collection.HTMLCollectionByAnchors(parser.documentHTMLToNode(self), false);
     }
 
-    pub fn get_all(self: *parser.DocumentHTML) !collection.HTMLCollection {
-        return try collection.HTMLCollectionAll(parser.documentHTMLToNode(self), true);
+    pub fn get_all(self: *parser.DocumentHTML) collection.HTMLAllCollection {
+        return collection.HTMLAllCollection.init(parser.documentHTMLToNode(self));
     }
 
     pub fn get_currentScript(self: *parser.DocumentHTML) !?*parser.Script {
@@ -260,4 +260,11 @@ test "Browser.HTML.Document" {
         .{ "document.cookie = 'favorite_food=tripe; SameSite=None; Secure'", "favorite_food=tripe; SameSite=None; Secure" },
         .{ "document.cookie", "name=Oeschger; favorite_food=tripe" },
     }, .{});
+
+    try runner.testCases(&.{
+        .{ "!document.all", "true" },
+        .{ "!!document.all", "false" },
+        .{ "document.all(5)", "[object HTMLParagraphElement]" },
+        .{ "document.all('content')", "[object HTMLDivElement]" },
+    }, .{});
 }
diff --git a/src/runtime/js.zig b/src/runtime/js.zig
index 6d7cd275..d3d68873 100644
--- a/src/runtime/js.zig
+++ b/src/runtime/js.zig
@@ -1221,6 +1221,7 @@ pub fn Env(comptime State: type, comptime WebApis: type) type {
 
             generateIndexer(Struct, template_proto);
             generateNamedIndexer(Struct, template_proto);
+            generateUndetectable(Struct, template.getInstanceTemplate());
         }
 
         // Even if a struct doesn't have a `constructor` function, we still
@@ -1420,6 +1421,32 @@ pub fn Env(comptime State: type, comptime WebApis: type) type {
             template_proto.setNamedProperty(configuration, null);
         }
 
+        fn generateUndetectable(comptime Struct: type, template: v8.ObjectTemplate) void {
+            const has_js_call_as_function = @hasDecl(Struct, "jsCallAsFunction");
+
+            if (has_js_call_as_function) {
+                template.setCallAsFunctionHandler(struct {
+                    fn callback(raw_info: ?*const v8.C_FunctionCallbackInfo) callconv(.c) void {
+                        const info = v8.FunctionCallbackInfo.initFromV8(raw_info);
+                        var caller = Caller(Self, State).init(info);
+                        defer caller.deinit();
+
+                        const named_function = comptime NamedFunction.init(Struct, "jsCallAsFunction");
+                        caller.method(Struct, named_function, info) catch |err| {
+                            caller.handleError(Struct, named_function, err, info);
+                        };
+                    }
+                }.callback);
+            }
+
+            if (@hasDecl(Struct, "mark_as_undetectable") and Struct.mark_as_undetectable) {
+                if (!has_js_call_as_function) {
+                    @compileError(@typeName(Struct) ++ ": mark_as_undetectable required jsCallAsFunction to be defined. This is a hard-coded requirement in V8, because mark_as_undetectable only exists for HTMLAllCollection which is also callable.");
+                }
+                template.markAsUndetectable();
+            }
+        }
+
         // Turns a Zig value into a JS one.
         fn zigValueToJs(
             templates: []v8.FunctionTemplate,