diff --git a/web/packages/selfhosted/test/polyfill/embed_default/test.ts b/web/packages/selfhosted/test/polyfill/embed_default/test.ts
index 7c2a6fd7fa17..f1d379ac1b1d 100644
--- a/web/packages/selfhosted/test/polyfill/embed_default/test.ts
+++ b/web/packages/selfhosted/test/polyfill/embed_default/test.ts
@@ -12,6 +12,7 @@ describe("Embed tag", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/embed_missing_type/test.ts b/web/packages/selfhosted/test/polyfill/embed_missing_type/test.ts
index 9cfcbd8f76ed..d9bc195de5d2 100644
--- a/web/packages/selfhosted/test/polyfill/embed_missing_type/test.ts
+++ b/web/packages/selfhosted/test/polyfill/embed_missing_type/test.ts
@@ -12,6 +12,7 @@ describe("Embed without type attribute", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/embed_unexpected_string/test.ts b/web/packages/selfhosted/test/polyfill/embed_unexpected_string/test.ts
index a76e5d398130..a65d53c47d0b 100644
--- a/web/packages/selfhosted/test/polyfill/embed_unexpected_string/test.ts
+++ b/web/packages/selfhosted/test/polyfill/embed_unexpected_string/test.ts
@@ -12,6 +12,7 @@ describe("Embed with unexpected string", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_clsid_with_embed/test.ts b/web/packages/selfhosted/test/polyfill/object_clsid_with_embed/test.ts
index a311d801fa97..49b4081bde00 100644
--- a/web/packages/selfhosted/test/polyfill/object_clsid_with_embed/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_clsid_with_embed/test.ts
@@ -12,6 +12,7 @@ describe("Object with clsid and embed", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_default/test.ts b/web/packages/selfhosted/test/polyfill/object_default/test.ts
index e22974525995..748f988bc063 100644
--- a/web/packages/selfhosted/test/polyfill/object_default/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_default/test.ts
@@ -12,6 +12,7 @@ describe("Object tag", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_double_object/test.ts b/web/packages/selfhosted/test/polyfill/object_double_object/test.ts
index b8cc1e7abffe..7d49c0ea8370 100644
--- a/web/packages/selfhosted/test/polyfill/object_double_object/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_double_object/test.ts
@@ -12,6 +12,7 @@ describe("Object with another object tag", () => {
 
     it("polyfills only the first tag with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-object />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_double_object_classid/test.ts b/web/packages/selfhosted/test/polyfill/object_double_object_classid/test.ts
index f376e7cb2eee..eed56c7ec9fc 100644
--- a/web/packages/selfhosted/test/polyfill/object_double_object_classid/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_double_object_classid/test.ts
@@ -12,6 +12,7 @@ describe("Object using classid with another object tag without classid", () => {
 
     it("polyfills only the second tag with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-object />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_flashvars/test.ts b/web/packages/selfhosted/test/polyfill/object_flashvars/test.ts
index 4af73bb2e6ab..3e59fbbb33e5 100644
--- a/web/packages/selfhosted/test/polyfill/object_flashvars/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_flashvars/test.ts
@@ -12,6 +12,7 @@ describe("Object tag", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_flashvars_in_url/test.ts b/web/packages/selfhosted/test/polyfill/object_flashvars_in_url/test.ts
index a6ee1da39af0..92f63e1d5496 100644
--- a/web/packages/selfhosted/test/polyfill/object_flashvars_in_url/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_flashvars_in_url/test.ts
@@ -12,6 +12,7 @@ describe("Object tag", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_ie_only/test.ts b/web/packages/selfhosted/test/polyfill/object_ie_only/test.ts
index 40585d72b323..fbe06346290b 100644
--- a/web/packages/selfhosted/test/polyfill/object_ie_only/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_ie_only/test.ts
@@ -12,6 +12,7 @@ describe("Object for old IE must work everywhere", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-object />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_missing_type/test.ts b/web/packages/selfhosted/test/polyfill/object_missing_type/test.ts
index eb2bb1a9431e..229117a3ddec 100644
--- a/web/packages/selfhosted/test/polyfill/object_missing_type/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_missing_type/test.ts
@@ -12,6 +12,7 @@ describe("Object without type attribute", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_missing_type_and_classid/test.ts b/web/packages/selfhosted/test/polyfill/object_missing_type_and_classid/test.ts
index 75cbc03902d3..502565d16a67 100644
--- a/web/packages/selfhosted/test/polyfill/object_missing_type_and_classid/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_missing_type_and_classid/test.ts
@@ -12,6 +12,7 @@ describe("Object without type and classid attributes", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-object />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_unexpected_string/test.ts b/web/packages/selfhosted/test/polyfill/object_unexpected_string/test.ts
index 4f8be646ea5a..07e0c01ac01c 100644
--- a/web/packages/selfhosted/test/polyfill/object_unexpected_string/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_unexpected_string/test.ts
@@ -12,6 +12,7 @@ describe("Object with unexpected string", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_with_ruffle_embed/test.ts b/web/packages/selfhosted/test/polyfill/object_with_ruffle_embed/test.ts
index 05d27e5128a1..c2c62eb6cfce 100644
--- a/web/packages/selfhosted/test/polyfill/object_with_ruffle_embed/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_with_ruffle_embed/test.ts
@@ -12,6 +12,7 @@ describe("Object with ruffle-embed tag", () => {
 
     it("already polyfilled with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/object_wrong_type/test.ts b/web/packages/selfhosted/test/polyfill/object_wrong_type/test.ts
index 5b164d0e99ed..284ae662a4a4 100644
--- a/web/packages/selfhosted/test/polyfill/object_wrong_type/test.ts
+++ b/web/packages/selfhosted/test/polyfill/object_wrong_type/test.ts
@@ -12,6 +12,7 @@ describe("Object with wrong type attribute value", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-embed />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/remove_object/test.ts b/web/packages/selfhosted/test/polyfill/remove_object/test.ts
index b76d5ed3c26a..c4ff6d77a43c 100644
--- a/web/packages/selfhosted/test/polyfill/remove_object/test.ts
+++ b/web/packages/selfhosted/test/polyfill/remove_object/test.ts
@@ -12,6 +12,7 @@ describe("Remove object", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-object />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });
diff --git a/web/packages/selfhosted/test/polyfill/spl/test.ts b/web/packages/selfhosted/test/polyfill/spl/test.ts
index 645f997fff71..47866dc017d7 100644
--- a/web/packages/selfhosted/test/polyfill/spl/test.ts
+++ b/web/packages/selfhosted/test/polyfill/spl/test.ts
@@ -12,6 +12,7 @@ describe("SPL", () => {
 
     it("polyfills with ruffle", async () => {
         await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-object />").waitForExist();
         const actual = await browser
             .$("#test-container")
             .getHTML({ includeSelectorTag: false, pierceShadowRoot: false });