diff --git a/doc/building-running.md b/doc/building-running.md
index 3adaa3c89..08cbe09f7 100644
--- a/doc/building-running.md
+++ b/doc/building-running.md
@@ -39,7 +39,6 @@ nix-build -A cardano-db-sync -o db-sync-node
 scripts/postgresql-setup.sh --createdb
 PGPASSFILE=config/pgpass db-sync-node/bin/cardano-db-sync \
     --config config/mainnet-config.yaml \
-    --genesis-file ../cardano-node/configuration/mainnet-genesis.json \
     --socket-path ../cardano-node/state-node-mainnet/node.socket \
     --schema-dir schema/
 ```
@@ -61,13 +60,11 @@ and then the two `db-sync` process run as:
 ```
 PGPASSFILE=config/pgpass ./cardano-db-sync-extended-exe \
     --config config/mainnet-config.yaml \
-    --genesis-file ../cardano-node/mainnet-genesis.json \
     --socket-path ../cardano-node/state-node-mainnet/node.socket --schema-dir schema/
 ```
 and
 ```
 PGPASSFILE=config/pgpass-testnet ./cardano-db-sync-extended-exe \
     --config config/testnet-config.yaml \
-    --genesis-file ../cardano-node/configuration/mainnet-ci/testnet-genesis.json \
     --socket-path ../cardano-node/state-node-testnet/node.socket --schema-dir schema/
 ```
diff --git a/nix/docker.nix b/nix/docker.nix
index 46c779b2c..2ea6b8a4e 100644
--- a/nix/docker.nix
+++ b/nix/docker.nix
@@ -5,31 +5,21 @@
 #
 #   docker load -i $(nix-build -A dockerImage --no-out-link)
 #
-#  cardano-db-sync and cardano-db-sync-extended are interchangeable in the following:
-#
-#  To launch with provided mainnet or testnet configuration
+# To launch with pre-loaded configuration, using the NETWORK env.
 #
 #    docker run \
 #      -v $PATH_TO/node-ipc:/node-ipc \
 #      -v $PATH_TO/pgpass:/configuration/pgpass \
 #      -e NETWORK=mainnet|testnet \
 #
-#  To launch the extended service:
+# Provide an (almost) complete command otherwise:
 #
-#    docker run \
-#      -v $PATH_TO/node-ipc:/node-ipc \
-#      -v $PATH_TO/pgpass:/configuration/pgpass \
-#      -e NETWORK=mainnet|testnet \
-#      -e EXTENDED=true
-#
-#  To launch with custom configuration, mount a dir containing configuration.yaml, genesis.json,
-#  and pgpass into /configuration
-#
-#    docker run \
-#      -v $PATH_TO/node-ipc:/node-ipc \
-#      -v $PATH_TO/configuration:/configuration \
-#      inputoutput/cardano-db-sync:<TAG>
+#   docker run -v $PWD/configuration/defaults/byron-mainnet:/configuration \
+#     inputoutput/cardano-db-sync run \
+#      --config /configuration/configuration.yaml \
+#      --socket-path /node-ipc/node.socket \
 #
+#  To launch the extended service include -e EXTENDED=true
 #  See the docker-compose.yml for demonstration of using Docker secrets instead of mounting a pgpass
 #
 ############################################################################
@@ -140,7 +130,7 @@ let
       export PGPASSFILE=/configuration/pgpass
       # set up /tmp (override with TMPDIR variable)
       mkdir -p -m 1777 tmp
-      if [[ -f /configuration/configuration.yaml ]]; then
+      if [[ -z "$NETWORK" ]]; then
         echo "Connecting to network specified in configuration.yaml"
         if [[ ! -z "''${EXTENDED}" ]] && [[ "''${EXTENDED}" == true ]]
         then
@@ -149,14 +139,10 @@ let
           DBSYNC=${cardano-db-sync}/bin/cardano-db-sync
         fi
          exec $DBSYNC \
-           --socket-path /node-ipc/node.socket \
-           --genesis-file /configuration/genesis.json \
-           --config /configuration/configuration.yaml \
-           --schema-dir ${../schema}
+           --schema-dir ${../schema} $@
       ${clusterStatements}
       else
-        echo "Please set a NETWORK environment variable to one of: mainnet/testnet"
-        echo "Or mount a /configuration volume containing: configuration.yaml, genesis.json, pgpass"
+        echo "Managed configuration for network "$NETWORK" does not exist"
       fi
     '';
   in dockerTools.buildImage {
diff --git a/nix/nixos/cardano-db-sync-service.nix b/nix/nixos/cardano-db-sync-service.nix
index 3388fe8fd..3b9fdcaa8 100644
--- a/nix/nixos/cardano-db-sync-service.nix
+++ b/nix/nixos/cardano-db-sync-service.nix
@@ -112,7 +112,6 @@ in {
         mkdir -p log-dir
         exec ${exec} \
           --config ${configFile} \
-          --genesis-file ${envConfig.genesisFile} \
           --socket-path "$CARDANO_NODE_SOCKET_PATH" \
           --schema-dir ${../../schema}
       '';