diff --git a/backend/backend/settings/deps/ledger.py b/backend/backend/settings/deps/ledger.py
index 14e72458d..5403f937d 100644
--- a/backend/backend/settings/deps/ledger.py
+++ b/backend/backend/settings/deps/ledger.py
@@ -141,8 +141,9 @@ def update_client_with_discovery(client, discovery_results):
                 peer.init_with_bundle({
                     'url': url,
                     'grpcOptions': {
-                        'grpc-max-send-message-length': 15,
-                        'grpc.ssl_target_name_override': peer_info['endpoint'].split(':')[0]
+                        'grpc.ssl_target_name_override': peer_info['endpoint'].split(':')[0],
+                        'grpc.max_send_message_length': -1,
+                        'grpc.max_receive_message_length': -1
                     },
                     'tlsCACerts': {'path': tls_root_cert.name},
                     'clientKey': {'path': LEDGER['peer']['clientKey']},  # use peer creds (mutual tls)
@@ -164,8 +165,9 @@ def update_client_with_discovery(client, discovery_results):
         orderer.init_with_bundle({
             'url': f"{orderer_info[0]['host']}:{orderer_info[0]['port']}",
             'grpcOptions': {
-                'grpc-max-send-message-length': 15,
-                'grpc.ssl_target_name_override': orderer_info[0]['host']
+                'grpc.ssl_target_name_override': orderer_info[0]['host'],
+                'grpc.max_send_message_length': -1,
+                'grpc.max_receive_message_length': -1
             },
             'tlsCACerts': {'path': tls_root_cert.name},
             'clientKey': {'path': LEDGER['peer']['clientKey']},  # use peer creds (mutual tls)
diff --git a/charts/substra-backend/Chart.yaml b/charts/substra-backend/Chart.yaml
index 6fc223015..2bd7642b0 100644
--- a/charts/substra-backend/Chart.yaml
+++ b/charts/substra-backend/Chart.yaml
@@ -1,7 +1,7 @@
 apiVersion: v1
 name: substra-backend
 home: https://substra.org/
-version: 1.0.0-alpha.19
+version: 1.0.0-alpha.20
 description: Main package for Substra
 icon: https://avatars1.githubusercontent.com/u/38098422?s=200&v=4
 sources:
diff --git a/charts/substra-backend/templates/configmap-server.yaml b/charts/substra-backend/templates/configmap-server.yaml
index 49c840070..584ecd917 100644
--- a/charts/substra-backend/templates/configmap-server.yaml
+++ b/charts/substra-backend/templates/configmap-server.yaml
@@ -30,8 +30,9 @@ data:
         "clientKey": "/var/hyperledger/tls/client/pair/tls.key",
         "clientCert": "/var/hyperledger/tls/client/pair/tls.crt",
         "grpcOptions": {
-          "grpc-max-send-message-length": 15,
-          "grpc.ssl_target_name_override": "{{ .Values.peer.host }}"
+          "grpc.ssl_target_name_override": "{{ .Values.peer.host }}",
+          "grpc.max_send_message_length": -1,
+          "grpc.max_receive_message_length": -1
         }
       }
     }