diff --git a/gateleen-routing/src/main/java/org/swisspush/gateleen/routing/Forwarder.java b/gateleen-routing/src/main/java/org/swisspush/gateleen/routing/Forwarder.java
index f5485552..3a049add 100755
--- a/gateleen-routing/src/main/java/org/swisspush/gateleen/routing/Forwarder.java
+++ b/gateleen-routing/src/main/java/org/swisspush/gateleen/routing/Forwarder.java
@@ -503,7 +503,7 @@ private Handler<AsyncResult<HttpClientResponse>> getAsyncHttpClientResponseHandl
 
             final LoggingWriteStream loggingWriteStream = new LoggingWriteStream(req.response(), loggingHandler, false);
             final Pump pump = Pump.pump(cRes, loggingWriteStream);
-            cRes.endHandler(v -> {
+            Handler<Void> cResEndHandler = v -> {
                 try {
                     req.response().end();
 
@@ -516,7 +516,14 @@ private Handler<AsyncResult<HttpClientResponse>> getAsyncHttpClientResponseHandl
                     // ignore because maybe already closed
                 }
                 vertx.runOnContext(event -> loggingHandler.log());
-            });
+            };
+            try {
+                cRes.endHandler(cResEndHandler);
+            } catch (IllegalStateException ex) {
+                log.warn("cRes.endHandler() failed", ex);
+                respondError(req, StatusCode.INTERNAL_SERVER_ERROR);
+                return;
+            }
             pump.start();
 
             Runnable unpump = () -> {