diff --git a/web/packages/core/src/internal/register-element.ts b/web/packages/core/src/internal/register-element.ts
index 2321b2a86015..b73aac13f5f4 100644
--- a/web/packages/core/src/internal/register-element.ts
+++ b/web/packages/core/src/internal/register-element.ts
@@ -86,6 +86,126 @@ export function registerElement(
                 continue;
             } else {
                 window.customElements.define(externalName, elementClass);
+
+                if (elementName === "ruffle-embed") {
+                    const orig = Object.getOwnPropertyDescriptor(
+                        Document.prototype,
+                        "embeds",
+                    );
+                    if (orig?.get) {
+                        const CACHE_SYM: unique symbol = Symbol(
+                            "ruffle_embeds_cache",
+                        );
+                        interface CachedCollection extends HTMLCollection {
+                            [CACHE_SYM]?: true;
+                        }
+                        Object.defineProperty(Document.prototype, "embeds", {
+                            get(this: Document): CachedCollection {
+                                const existing = (
+                                    this as unknown as Record<
+                                        symbol,
+                                        HTMLCollection
+                                    >
+                                )[CACHE_SYM];
+                                if (existing) {
+                                    return existing;
+                                }
+
+                                const nodes = (): NodeListOf<Element> =>
+                                    this.querySelectorAll(
+                                        "embed, ruffle-embed",
+                                    );
+
+                                const base = Object.create(
+                                    HTMLCollection.prototype,
+                                ) as HTMLCollection;
+
+                                Object.defineProperty(base, "length", {
+                                    enumerable: true,
+                                    configurable: true,
+                                    get() {
+                                        return nodes().length;
+                                    },
+                                });
+
+                                base.item = function (
+                                    index: number,
+                                ): Element | null {
+                                    return nodes()[index] ?? null;
+                                };
+
+                                base.namedItem = function (
+                                    name: string,
+                                ): Element | null {
+                                    const list = nodes();
+                                    for (const el of list) {
+                                        const htmlEl = el as HTMLElement;
+                                        if (
+                                            name &&
+                                            (htmlEl.getAttribute("name") ===
+                                                name ||
+                                                htmlEl.id === name)
+                                        ) {
+                                            return htmlEl;
+                                        }
+                                    }
+                                    return null;
+                                };
+
+                                (base as Iterable<Element>)[Symbol.iterator] =
+                                    function* (): Iterator<Element> {
+                                        for (const el of nodes()) {
+                                            yield el;
+                                        }
+                                    };
+
+                                const proxy = new Proxy(base, {
+                                    get(target, prop, receiver) {
+                                        if (typeof prop === "string") {
+                                            const index = Number(prop);
+                                            if (
+                                                !Number.isNaN(index) &&
+                                                index >= 0
+                                            ) {
+                                                return nodes()[index];
+                                            }
+                                        }
+                                        return Reflect.get(
+                                            target,
+                                            prop,
+                                            receiver,
+                                        );
+                                    },
+                                    has(target, prop) {
+                                        if (typeof prop === "string") {
+                                            const index = Number(prop);
+                                            if (
+                                                !Number.isNaN(index) &&
+                                                index >= 0
+                                            ) {
+                                                return index < nodes().length;
+                                            }
+                                        }
+                                        return Reflect.has(target, prop);
+                                    },
+                                }) as CachedCollection;
+
+                                proxy[CACHE_SYM] = true;
+
+                                (
+                                    this as unknown as Record<
+                                        symbol,
+                                        CachedCollection
+                                    >
+                                )[CACHE_SYM] = proxy;
+
+                                return proxy;
+                            },
+                            configurable: true,
+                            enumerable: true,
+                        });
+                    }
+                }
             }
 
             privateRegistry[elementName] = {
diff --git a/web/packages/selfhosted/test/polyfill/document_embeds/index.html b/web/packages/selfhosted/test/polyfill/document_embeds/index.html
new file mode 100644
index 000000000000..d2834d4e84c8
--- /dev/null
+++ b/web/packages/selfhosted/test/polyfill/document_embeds/index.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="utf-8" />
+        <title>DOCUMENT EMBEDS</title>
+    </head>
+
+    <body>
+        <div id="test-container">
+            <embed id="emb1" name="fl" src="/test_assets/example.swf" width="200" height="200"></embed>
+            <embed id="emb2" name="fl" src="/test_assets/example.swf" width="200" height="200"></embed>
+            <embed id="emb3" name="fl" src="/test_assets/example.swf" width="200" height="200"></embed>
+        </div>
+        <ul id="output"></ul>
+    </body>
+</html>
diff --git a/web/packages/selfhosted/test/polyfill/document_embeds/test.ts b/web/packages/selfhosted/test/polyfill/document_embeds/test.ts
new file mode 100644
index 000000000000..8f7f40af9c5d
--- /dev/null
+++ b/web/packages/selfhosted/test/polyfill/document_embeds/test.ts
@@ -0,0 +1,50 @@
+import { injectRuffleAndWait, openTest, playAndMonitor } from "../../utils.js";
+import { expect } from "chai";
+
+describe("Document embeds", () => {
+    it("loads the test", async () => {
+        await openTest(browser, `polyfill/document_embeds`);
+    });
+
+    it("Accesses the right number of elements with ruffle", async () => {
+        async function countDocumentEmbeds() {
+            return await browser.execute(() => {
+                return document.embeds?.length ?? 0;
+            });
+        }
+
+        async function documentEmbedsSelfIdentity() {
+            return await browser.execute(() => {
+                return document.embeds === document.embeds;
+            });
+        }
+
+        async function removeEl(selector: string) {
+            const el = await $(selector);
+            await browser.execute((element) => {
+                element.remove();
+            }, el);
+        }
+
+        await injectRuffleAndWait(browser);
+        await playAndMonitor(
+            browser,
+            await browser.$("#test-container").$("ruffle-embed#emb1"),
+        );
+        await playAndMonitor(
+            browser,
+            await browser.$("#test-container").$("ruffle-embed#emb2"),
+        );
+        await playAndMonitor(
+            browser,
+            await browser.$("#test-container").$("ruffle-embed#emb3"),
+        );
+        const documentEmbedsIdentity = await documentEmbedsSelfIdentity();
+        expect(documentEmbedsIdentity).to.equal(true);
+        const embeds1 = await countDocumentEmbeds();
+        expect(embeds1).to.equal(3);
+        await removeEl("#emb1");
+        const embeds2 = await countDocumentEmbeds();
+        expect(embeds2).to.equal(2);
+    });
+});