diff --git a/README.md b/README.md
index 9dcc178..ac93170 100644
--- a/README.md
+++ b/README.md
@@ -123,6 +123,7 @@ You can read [the article](https://medium.com/@BtcpayServer/hosting-btcpay-serve
 * `ACME_CA_URI`: The API endpoint to ask for HTTPS certificate (Default: `https://acme-v01.api.letsencrypt.org/directory`)
 * `BTCPAY_HOST_SSHKEYFILE`: Optional, SSH private key that BTCPay can use to connect to this VM's SSH server. This key will be copied to BTCPay's data directory
 * `BTCPAY_SSHTRUSTEDFINGERPRINTS`: Optional, BTCPay will ensure that it is connecting to the expected SSH server by checking the host's public key against these fingerprints
+* `BTCPAYGEN_DOCKER_IMAGE`: Optional, Specify which generator image to use if you have customized the C# generator. Set to `btcpayserver/docker-compose-generator:local` to build the generator locally at runtime.
 
 # Tooling
 
@@ -270,20 +271,9 @@ BTCPAY_SSHKEYFILE=/datadir/id_rsa
 1. Add support for your crypto to [NBitcoin](https://github.com/MetacoSA/NBitcoin/tree/master/NBitcoin.Altcoins), [NBxplorer](https://github.com/dgarage/NBXplorer), and [BTCPayServer](https://github.com/btcpayserver/btcpayserver). (Use examples from other coins)
 2. Create your own docker image ([Example for BTC](https://hub.docker.com/r/nicolasdorier/docker-bitcoin/))
 3. Create a docker-compose fragment ([Example for BTC](docker-compose-generator/docker-fragments/bitcoin.yml))
-4. Add your CryptoDefinition ([Example for BTC](docker-compose-generator/src/CryptoDefinition.cs))
-
-When testing your coin, **DO NOT USE `build.sh`**, since it uses a pre-built docker image.
-
-Instead, install [.NET Core 2.1 SDK](https://www.microsoft.com/net/download/windows) and run:
-
-```bash
-BTCPAYGEN_CRYPTO1="EXAMPLE-COIN"
-BTCPAYGEN_SUBNAME="test"
-cd docker-compose-generator/src
-dotnet run
-```
-
-This will generate your docker-compose in the `Generated` folder, which you can then run and test.
+4. Add your coin to CryptoDefinition ([Example for BTC](docker-compose-generator/src/CryptoDefinition.cs))
+5. Tell the setup script to build the docker compose generator image locally by specifying the environment variable `BTCPAYGEN_DOCKER_IMAGE` to `btcpayserver/docker-compose-generator:local`
+6. Configure the BtcPay environment variables as usual and run [build.sh](build.sh) (or [build.ps1](build.ps1)) to generate the docker compose script under `Generated`
 
 Note that BTCPayServer developers will not spend excessive time testing your image, so make sure it works.
 
diff --git a/build.ps1 b/build.ps1
index 5b6e7ab..9425aee 100755
--- a/build.ps1
+++ b/build.ps1
@@ -1,7 +1,13 @@
 # This script will run docker-compose-generator in a container to generate the yml files
 if (-not ($BTCPAYGEN_DOCKER_IMAGE)) { $BTCPAYGEN_DOCKER_IMAGE = "btcpayserver/docker-compose-generator" }
 
-docker pull $BTCPAYGEN_DOCKER_IMAGE:
+If (-not ($BTCPAYGEN_DOCKER_IMAGE)) { $BTCPAYGEN_DOCKER_IMAGE = "btcpayserver/docker-compose-generator" }
+If($BTCPAYGEN_DOCKER_IMAGE -eq "btcpayserver/docker-compose-generator:local"){
+	docker build docker-compose-generator --tag $BTCPAYGEN_DOCKER_IMAGE
+} Else {
+	docker pull $BTCPAYGEN_DOCKER_IMAGE
+}
+
 docker run -v "$(Get-Location)\Generated:/app/Generated" `
            -v "$(Get-Location)\docker-compose-generator\docker-fragments:/app/docker-fragments" `
            -e "BTCPAYGEN_CRYPTO1=$BTCPAYGEN_CRYPTO1" `
diff --git a/build.sh b/build.sh
index 9234020..232110b 100755
--- a/build.sh
+++ b/build.sh
@@ -1,7 +1,13 @@
 #!/bin/bash
 
+if [ "$BTCPAYGEN_DOCKER_IMAGE" == "btcpayserver/docker-compose-generator:local" ]
+then
+    docker build docker-compose-generator --tag $BTCPAYGEN_DOCKER_IMAGE
+else
+    docker pull ${BTCPAYGEN_DOCKER_IMAGE:-"btcpayserver/docker-compose-generator"}
+fi
+
 # This script will run docker-compose-generator in a container to generate the yml files
-docker pull ${BTCPAYGEN_DOCKER_IMAGE:-"btcpayserver/docker-compose-generator"}
 docker run -v "$(pwd)/Generated:/app/Generated" \
            -v "$(pwd)/docker-compose-generator/docker-fragments:/app/docker-fragments" \
            -e "BTCPAYGEN_CRYPTO1=$BTCPAYGEN_CRYPTO1" \