diff --git a/pages/404.html b/pages/404.html
index 8e9f51e568..bb1d22f77e 100644
--- a/pages/404.html
+++ b/pages/404.html
@@ -5,8 +5,9 @@
   const refmanRegex = /^\/distrib\/(.*)\/refman\//;
   const V80refmanRegex = /^\/distrib\/V8.0\/doc\//;
   const stdlibDistribRegex = /^\/distrib\/(.*)\/stdlib\//;
-  const bugRegexSimplified = /^\/bug\/(.*)/;
-  const bugRegex = /^\/bugs\/show_bug\.cgi\?id=(.*)/;
+  const bugSimplifiedRegex = /^\/bug\/(.*)/;
+  const bugPath = "/bugs/show_bug.cgi"
+  const bugSearchRegex = /^\?id=(.*)/;
   if (stdlibRegex.test(path)) {
     window.location = path.replace(stdlibRegex, "/doc/<#CURRENTVERSIONTAG>/stdlib/");
   } else if (refmanRegex.test(path)) {
@@ -27,12 +28,12 @@
     }
   } else if (V80refmanRegex.test(path)) {
     window.location = path.replace(V80refmanRegex, "/doc/V8.0/doc/");
-  } else if (bugRegexSimplified.test(path)) {
-    const bugId = path.match(bugRegexSimplified)[1];
+  } else if (bugSimplifiedRegex.test(path)) {
+    const bugId = path.match(bugSimplifiedRegex)[1];
     // To avoid having to rely on the correspondence table from the migration, we redirect to the search page
     window.location = "https://github.com/coq/coq/issues?q=is%3Aissue%20%22Original%20bug%20ID%3A%20BZ%23" + bugId + "%22"
-  } else if (bugRegex.test(path)) {
-    const bugId = path.match(bugRegex)[1];
+  } else if (bugPath == path && bugSearchRegex.test(window.location.search)) {
+    const bugId = window.location.search.match(bugSearchRegex)[1];
     window.location = "https://github.com/coq/coq/issues?q=is%3Aissue%20%22Original%20bug%20ID%3A%20BZ%23" + bugId + "%22"
   } else {
     document.write("<h1>Not found</h1>");