diff --git a/boost.module b/boost.module
index 64d07ac780c53ab17297f402690605702aa980ad..4831921580851e13afcdc39a03e62261230b5458 100644
--- a/boost.module
+++ b/boost.module
@@ -92,9 +92,12 @@ function boost_init() {
   // TODO: check interaction with other modules that use ob_start(); this
   // may have to be moved to an earlier stage of the page request.
   if (!variable_get('cache', CACHE_DISABLED) && BOOST_ENABLED) {
+    // We only support GET requests by anonymous visitors:
     global $user;
     if (empty($user->uid) && $_SERVER['REQUEST_METHOD'] == 'GET') {
-      if (boost_is_cacheable($_GET['q']))
+      // Make sure no query string (in addition to ?q=) was set, and that
+      // the page is cacheable according to our current configuration:
+      if (count($_GET) == 1 && boost_is_cacheable($_GET['q']))
         ob_start('_boost_ob_handler');
     }
   }
diff --git a/htaccess/boosted.txt b/htaccess/boosted.txt
index 1e719e3a3229d0bfbe2d87c9a0ae222e5cfc78fe..f89b08425d387149d9df766be366feae58eceba4 100644
--- a/htaccess/boosted.txt
+++ b/htaccess/boosted.txt
@@ -90,17 +90,17 @@ DirectoryIndex index.php
   RewriteCond %{HTTP_COOKIE} !DRUPAL_UID
   RewriteCond %{REQUEST_METHOD} ^GET$
   RewriteCond %{QUERY_STRING} ^$
-  RewriteCond %{DOCUMENT_ROOT}/cache/%{HTTP_HOST}/0/%{REQUEST_URI} -d
-  RewriteCond %{DOCUMENT_ROOT}/cache/%{HTTP_HOST}/0/%{REQUEST_URI}/index.html -f
-  RewriteRule ^(.*)$ cache/%{HTTP_HOST}/0/$1/index.html [L]
+  RewriteCond %{DOCUMENT_ROOT}/cache/%{SERVER_NAME}/0/%{REQUEST_URI} -d
+  RewriteCond %{DOCUMENT_ROOT}/cache/%{SERVER_NAME}/0/%{REQUEST_URI}/index.html -f
+  RewriteRule ^(.*)$ cache/%{SERVER_NAME}/0/$1/index.html [L]
   RewriteCond %{REQUEST_URI} !^/cache
   RewriteCond %{REQUEST_URI} !^/user/login
   RewriteCond %{REQUEST_URI} !^/admin
   RewriteCond %{HTTP_COOKIE} !DRUPAL_UID
   RewriteCond %{REQUEST_METHOD} ^GET$
   RewriteCond %{QUERY_STRING} ^$
-  RewriteCond %{DOCUMENT_ROOT}/cache/%{HTTP_HOST}/0/%{REQUEST_URI}.html -f
-  RewriteRule ^(.*)$ cache/%{HTTP_HOST}/0/$1.html [L]
+  RewriteCond %{DOCUMENT_ROOT}/cache/%{SERVER_NAME}/0/%{REQUEST_URI}.html -f
+  RewriteRule ^(.*)$ cache/%{SERVER_NAME}/0/$1.html [L]
   # BOOST END
 
   # Rewrite current-style URLs of the form 'index.php?q=x'.