diff --git a/gateway-server/src/main/java/org/apache/knox/gateway/websockets/GatewayWebsocketHandler.java b/gateway-server/src/main/java/org/apache/knox/gateway/websockets/GatewayWebsocketHandler.java
index f275ee9eeb..650bc0681d 100644
--- a/gateway-server/src/main/java/org/apache/knox/gateway/websockets/GatewayWebsocketHandler.java
+++ b/gateway-server/src/main/java/org/apache/knox/gateway/websockets/GatewayWebsocketHandler.java
@@ -190,8 +190,8 @@ public void beforeRequest(final Map<String, List<String>> headers) {
               headers.put("Host", Arrays.asList(backendURL.getHost() + ":" + backendURL.getPort()));
             } catch (final URISyntaxException e) {
               LOG.onError(String.format(Locale.ROOT,
-                  "Error getting backend url, this could cause 'Host does not match SNI' exception. Cause: ",
-                  e.toString()));
+                  "Error getting backend url, this could cause 'Host does not match SNI' exception. Cause: %s",
+                  e));
             }
           }
         }).build();