diff --git a/packages/gatsby-link/index.d.ts b/packages/gatsby-link/index.d.ts
index 1569e23435ef1..05bdcf43f546d 100644
--- a/packages/gatsby-link/index.d.ts
+++ b/packages/gatsby-link/index.d.ts
@@ -8,4 +8,6 @@ export interface GatsbyLinkProps extends NavLinkProps {
 
 export const navigateTo: (path: string) => void;
 
+export const withPrefix: (path: string) => string;
+
 export default class GatsbyLink extends React.Component<GatsbyLinkProps> { }