diff --git a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/HttpConnector2.java b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/HttpConnector2.java
index 3782a19e4..a84b26955 100644
--- a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/HttpConnector2.java
+++ b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/HttpConnector2.java
@@ -142,9 +142,10 @@ public class HttpConnector2 {
 				throw new CollectorException("4xx error: request will not be repeated. " + report);
 			}
 			if (is5xx(urlConn.getResponseCode())) {
-				// SERVER SIDE ERRORS RETRY ONLY on 503
 				switch (urlConn.getResponseCode()) {
+					case HttpURLConnection.HTTP_BAD_GATEWAY:
 					case HttpURLConnection.HTTP_UNAVAILABLE:
+					case HttpURLConnection.HTTP_GATEWAY_TIMEOUT:
 						if (retryAfter > 0) {
 							log
 								.warn(