diff --git a/types/styled-components/index.d.ts b/types/styled-components/index.d.ts
index 924699dd3a..e28b05066e 100644
--- a/types/styled-components/index.d.ts
+++ b/types/styled-components/index.d.ts
@@ -446,6 +446,7 @@ export class ServerStyleSheet {
         readableStream: NodeJS.ReadableStream
     ): NodeJS.ReadableStream;
     readonly instance: this;
+    seal(): void;
 }
 
 type StyleSheetManagerProps =
diff --git a/types/styled-components/test/index.tsx b/types/styled-components/test/index.tsx
index 7108f737f7..bae94072ec 100644
--- a/types/styled-components/test/index.tsx
+++ b/types/styled-components/test/index.tsx
@@ -472,6 +472,7 @@ const sheet = new ServerStyleSheet();
 const html = sheet.collectStyles(<SSRTitle>Hello world</SSRTitle>);
 const styleHtml = sheet.getStyleTags();
 const styleElement = sheet.getStyleElement();
+sheet.seal();
 
 const sheet2 = new ServerStyleSheet();
 const element = (