diff --git a/build/scripts/Complement.Dockerfile b/build/scripts/Complement.Dockerfile
index c703db6bc..401695abf 100644
--- a/build/scripts/Complement.Dockerfile
+++ b/build/scripts/Complement.Dockerfile
@@ -12,7 +12,6 @@ COPY . .
 RUN go build ./cmd/dendrite-monolith-server
 RUN go build ./cmd/generate-keys
 RUN go build ./cmd/generate-config
-RUN ./generate-config --ci > dendrite.yaml
 RUN ./generate-keys --private-key matrix_key.pem
 
 ENV SERVER_NAME=localhost
@@ -21,6 +20,6 @@ EXPOSE 8008 8448
 # At runtime, generate TLS cert based on the CA now mounted at /ca
 # At runtime, replace the SERVER_NAME with what we are told
 CMD ./generate-keys --server $SERVER_NAME --tls-cert server.crt --tls-key server.key --tls-authority-cert /ca/ca.crt --tls-authority-key /ca/ca.key && \
- sed -i "s/server_name: localhost/server_name: ${SERVER_NAME}/g" dendrite.yaml && \
+ ./generate-config -server $SERVER_NAME --ci > dendrite.yaml && \
  cp /ca/ca.crt /usr/local/share/ca-certificates/ && update-ca-certificates && \
  ./dendrite-monolith-server --tls-cert server.crt --tls-key server.key --config dendrite.yaml