diff --git a/extension/src/webcat/response.ts b/extension/src/webcat/response.ts
index c541ff4..7330c7e 100644
--- a/extension/src/webcat/response.ts
+++ b/extension/src/webcat/response.ts
@@ -444,6 +444,7 @@ export class ResponseValidator {
         errorpage(
           details,
           new WebcatError(WebcatErrorCode.File.MISSING, [pathname]),
+          true,
         );
         return;
       }
@@ -466,6 +467,7 @@ export class ResponseValidator {
             String(manifest_hash),
             String(Uint8ArrayToBase64Url(new Uint8Array(content_hash))),
           ]),
+          true,
         );
         return;
       }
diff --git a/extension/src/webcat/ui.ts b/extension/src/webcat/ui.ts
index 7ce40f9..e9748a9 100644
--- a/extension/src/webcat/ui.ts
+++ b/extension/src/webcat/ui.ts
@@ -81,6 +81,7 @@ export function setErrorIcon(tabId: number) {
 export async function errorpage(
   details: Stateful<RequestDetails>,
   error?: WebcatError,
+  replace = !details.state.isFrame,
 ) {
   const tabIds = new Set<number>();
   const frameLookups = [];
@@ -134,7 +135,7 @@ export async function errorpage(
     tabUpdates.push(
       browser.tabs.update(tabId, {
         url: errorPageUrl,
-        loadReplace: !details.state.isFrame,
+        loadReplace: replace,
       }),
     ),
   );