diff --git a/internal/component/instances/php/list_uri_prefixes.php b/internal/component/instances/php/list_uri_prefixes.php
index 6df7248..fd4b5e7 100644
--- a/internal/component/instances/php/list_uri_prefixes.php
+++ b/internal/component/instances/php/list_uri_prefixes.php
@@ -23,6 +23,9 @@ function list_prefixes() {
 }
 
 function getTriplestorePrefixes($engine, &$prefixes) {
+    // some adapters don't support a query method!
+    if (!method_exists($engine, 'directQuery')) return NULL;
+
     $results = $engine->directQuery('
     select distinct ?base where {
         {
diff --git a/internal/core/bootstrap/resolver-blocked.txt b/internal/core/bootstrap/resolver-blocked.txt
index 31b4445..5273692 100644
--- a/internal/core/bootstrap/resolver-blocked.txt
+++ b/internal/core/bootstrap/resolver-blocked.txt
@@ -12,5 +12,5 @@ urn:
 http://d-nb.info/gnd/
 http://erlangen-crm.org/
 http://id.gnm.de/ont/
-http://zotero.org/
+http://www.zotero.org/
 https://api.zotero.org/