diff -r 9175ea22f1b1 -r 8a5bb4b48b85 server/src/app/Services/BnfResolver.php
--- a/server/src/app/Services/BnfResolver.php	Thu Feb 09 17:22:58 2017 +0100
+++ b/server/src/app/Services/BnfResolver.php	Fri Feb 10 12:03:12 2017 +0100
@@ -3,6 +3,8 @@
 
 use Cache;
 use CorpusParole\Services\BnfResolverInterface;
+use CorpusParole\Services\BnfResolverTimeoutException;
+use EasyRdf;
 
 class BnfResolver implements BnfResolverInterface {
 
@@ -84,7 +86,20 @@
         }
         $query .= "}";
 
-        $docs = $this->sparqlClient->query($query);
+        try {
+            $docs = $this->sparqlClient->query($query);
+        } catch (EasyRdf\Exception $e) {
+            $code = 0;
+            if(method_exists($e, 'getCode')) {
+                $code = $e->getCode();
+            }
+            $message = $e->getMessage();
+            if($code == 400 || ($code == 0 && stripos($message, 'timed out')>=0) ) {
+                throw new BnfResolverTimeoutException("Query to bnf server timed out.");
+            }
+            // reraise the original exception
+            throw $e;
+        }
 
         $resultsRaw = [];