diff --git a/server/routes/index.ts b/server/routes/index.ts
index db5685c3b..fb7a421e5 100644
--- a/server/routes/index.ts
+++ b/server/routes/index.ts
@@ -151,7 +151,7 @@ router.get("/robots.txt", (ctx) => {
 router.get("/opensearch.xml", (ctx) => {
   ctx.type = "text/xml";
 
-  ctx.body = opensearchResponse();
+  ctx.body = opensearchResponse(ctx.request.URL.origin);
 });
 
 router.get("/share/:shareId", renderShare);
diff --git a/server/utils/opensearch.ts b/server/utils/opensearch.ts
index 8fc3e511f..044cdd25b 100644
--- a/server/utils/opensearch.ts
+++ b/server/utils/opensearch.ts
@@ -1,12 +1,12 @@
-export const opensearchResponse = (): string => {
+export const opensearchResponse = (baseUrl: string): string => {
   return `
 <OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/" xmlns:moz="http://www.mozilla.org/2006/browser/search/">
   <ShortName>Outline</ShortName>
   <Description>Search Outline</Description>
   <InputEncoding>UTF-8</InputEncoding>
-  <Image width="16" height="16" type="image/x-icon">${process.env.URL}/favicon.ico</Image>
-  <Url type="text/html" method="get" template="${process.env.URL}/search/{searchTerms}?ref=opensearch"/>
-  <moz:SearchForm>${process.env.URL}/search</moz:SearchForm>
+  <Image width="16" height="16" type="image/x-icon">${baseUrl}/favicon.ico</Image>
+  <Url type="text/html" method="get" template="${baseUrl}/search/{searchTerms}?ref=opensearch"/>
+  <moz:SearchForm>${baseUrl}/search</moz:SearchForm>
 </OpenSearchDescription>
 `;
 };