diff --git a/controllers/scriptStorage.js b/controllers/scriptStorage.js
index e30bfa64a..60ce1050e 100644
--- a/controllers/scriptStorage.js
+++ b/controllers/scriptStorage.js
@@ -385,6 +385,16 @@ exports.sendScript = function (aReq, aRes, aNext) {
   exports.getSource(aReq, function (aScript, aStream) {
     let chunks = [];
     let updateURL = null;
+    let updateUtf = null;
+
+    let matches = null;
+    let rAnyLocalMetaUrl = new RegExp('^https?://(?:openuserjs\.org|oujs\.org' +
+      (isDev ? '|localhost:' + (process.env.PORT || 8080) : '') +
+        ')/(?:meta|install|src/scripts)/(.+?)/(.+?)\.meta\.js$');
+    let hasAlternateLocalUpdateURL = false;
+
+    let rAnyLocalHost =  new RegExp('^(?:openuserjs\.org|oujs\.org' +
+      (isDev ? '|localhost:' + (process.env.PORT || 8080) : '') + ')');
 
     if (!aScript) {
       aNext();
@@ -392,27 +402,52 @@ exports.sendScript = function (aReq, aRes, aNext) {
     }
 
     if (process.env.FORCE_BUSY_UPDATEURL_CHECK === 'true') {
+      // `@updateURL` must be exact here for OUJS hosted checks
+      //   e.g. no `search`, no `hash`
+
       updateURL = findMeta(aScript.meta, 'UserScript.updateURL.0.value');
       if (updateURL) {
-        updateURL = URL.parse(updateURL);
-        if (/^(?:localhost|openuserjs|oujs)\.org$/.test(updateURL.host) &&
-          /^\/(?:install|src)/.test(updateURL.pathname) &&
-            /\.js$/.test(updateURL.pathname))
-        {
-          // NOTE: Don't serve the script anywhere in this mode
-          aRes.set('Warning', '199 ' + aReq.headers.host + ' Invalid @updateURL');
+
+        // Check for decoding error
+        try {
+          updateUtf = decodeURIComponent(updateURL);
+        } catch (aE) {
+          aRes.set('Warning', '199 ' + aReq.headers.host +
+            rfc2047.encode(' Invalid @updateURL'));
           aRes.status(444).send();
           return;
         }
+
+        // Validate `author` and `name` (installNameBase) to this scripts meta only
+        let matches = updateUtf.match(rAnyLocalMetaUrl);
+        if (matches) {
+          if (cleanFilename(aScript.author, '').toLowerCase() +
+            '/' + cleanFilename(aScript.name, '') === matches[1].toLowerCase() + '/' + matches[2])
+          {
+            // Same script
+          } else {
+            hasAlternateLocalUpdateURL = true;
+          }
+        } else {
+          // Allow offsite checks
+          updateURL = URL.parse(updateURL);
+          if (rAnyLocalHost.test(updateURL.host)) {
+            hasAlternateLocalUpdateURL = true;
+          }
+        }
       } else {
         if (!aScript.isLib) {
-          // NOTE: Don't serve the script anywhere in this mode and if absent
-
-          aRes.set('Warning', rfc2047.encode('199 ' + aReq.headers.host + 'Missing @updateURL'));
-          aRes.status(444).send();
-          return;
+          // Don't serve the script anywhere in this mode and if absent
+          hasAlternateLocalUpdateURL = true;
         }
       }
+
+      if (hasAlternateLocalUpdateURL) {
+        aRes.set('Warning', '199 ' + aReq.headers.host +
+          rfc2047.encode(' Invalid @updateURL in lockdown'));
+        aRes.status(444).send();
+        return;
+      }
     }
 
     // Send the script
diff --git a/libs/modelParser.js b/libs/modelParser.js
index 863905da4..61877ab14 100644
--- a/libs/modelParser.js
+++ b/libs/modelParser.js
@@ -204,8 +204,9 @@ var parseScript = function (aScript) {
 
   var downloadURL = null;
   var downloadUtf = null;
-  var rAnySourceUrl = new RegExp('^https?://(?:openuserjs\.org|localhost:' +
-    (process.env.PORT || 8080) + ')/(?:install|src/scripts)\/(.+?)/(.+?)((?:\.min)?\.user\.js)$');
+  var rAnyLocalScriptUrl = new RegExp('^https?://(?:openuserjs\.org|oujs\.org' +
+    (isDev ? '|localhost:' + (process.env.PORT || 8080) : '') +
+      ')/(?:install|src/scripts)/(.+?)/(.+?)((?:\.min)?(?:\.user)?\.js)$');
 
   // Temporaries
   var htmlStub = null;
@@ -400,14 +401,15 @@ var parseScript = function (aScript) {
 
     } finally {
       if (!script.hasInvalidDownloadURL)  {
-        matches = downloadUtf.match(rAnySourceUrl);
-
+        matches = downloadUtf.match(rAnyLocalScriptUrl);
         if (matches) {
           if (matches[1].toLowerCase() === script.authorSlug.toLowerCase() &&
             matches[2] === script.nameSlug) {
-
-            if (matches[3] === '.user.js') {
+            if (/(?:\.min)?\.user\.js$/.test(matches[3])) {
+              // Same script
+            } else {
               script.hasAlternateDownloadURL = true;
+              script.showMinficationNotices = true;
             }
           } else {
             script.hasAlternateDownloadURL = true;