diff --git a/extensions/adblock.c b/extensions/adblock.c
index 93e92bb9..21481e5c 100644
--- a/extensions/adblock.c
+++ b/extensions/adblock.c
@@ -650,6 +650,7 @@ adblock_is_matched_by_key (const gchar* req_uri,
     gboolean ret = FALSE;
     gchar sig[SIGNATURE_SIZE + 1];
 
+    memset (&sig[0], 0, sizeof (sig));
     /* Signatures are made on pattern, so we need to convert url to a pattern as well */
     guri = adblock_fixup_regexp ("", (gchar*)req_uri);
     uri = guri->str;
@@ -665,7 +666,7 @@ adblock_is_matched_by_key (const gchar* req_uri,
         if (!regex || g_list_find (regex_bl, regex))
             continue;
         ret = adblock_check_rule (regex, sig, req_uri, page_uri);
-        if (!ret)
+        if (ret)
             break;
         regex_bl = g_list_prepend (regex_bl, regex);
     }