diff --git a/docker-compose.yml b/docker-compose.yml
index 058baa7..d6d7f5a 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -18,9 +18,11 @@ services:
     build:
       context: gw-build
       dockerfile: Dockerfile
+      additional_contexts:
+        modules: modules
       args:
         IGNITION_VERSION: ${IGNITION_VERSION:-latest}
-        SUPPLEMENTAL_MODULES: "mqtttransmissionnightly"
+        SUPPLEMENTAL_MODULES: ""
         BASE_GWBK_NAME: base.gwbk
         GATEWAY_ADMIN_USERNAME: admin
       secrets:
diff --git a/gw-build/Dockerfile b/gw-build/Dockerfile
index 4e4093a..ec6d524 100644
--- a/gw-build/Dockerfile
+++ b/gw-build/Dockerfile
@@ -20,6 +20,10 @@ ARG SUPPLEMENTAL_MQTTTRANSMISSIONNIGHTLY_DOWNLOAD_URL="https://ignition-modules-
 ARG SUPPLEMENTAL_MQTTTRANSMISSIONNIGHTLY_DOWNLOAD_SHA256="notused"
 ARG SUPPLEMENTAL_MODULES
 
+# Local MQTT module built/placed in the sibling `modules/` directory (see the
+# "modules" additional build context wired up in docker-compose.yml)
+ARG SUPPLEMENTAL_MQTT_LOCAL_MODULE=MQTTtransmitter.modl
+
 # Set working directory for this prep image and ensure that exits from sub-shells bubble up and report an error
 WORKDIR /root
 SHELL [ "/usr/bin/env", "-S", "bash", "-euo", "pipefail", "-O", "inherit_errexit", "-c" ]
@@ -28,6 +32,9 @@ SHELL [ "/usr/bin/env", "-S", "bash", "-euo", "pipefail", "-O", "inherit_errexit
 COPY --chmod=0755 retrieve-modules.sh .
 RUN if [ -n "${SUPPLEMENTAL_MODULES:-}" ]; then ./retrieve-modules.sh -m "${SUPPLEMENTAL_MODULES}"; fi
 
+# Pull in the MQTT module straight from the local modules/ folder
+COPY --from=modules ${SUPPLEMENTAL_MQTT_LOCAL_MODULE} ./
+
 # Set CERTIFICATES/EULAS acceptance in gateway backup config db
 COPY *.gwbk ./
 COPY --chmod=0755 register-module.sh register-password.sh ./
diff --git a/modules/MQTT-Transmission-signed (1).modl b/modules/MQTTtransmitter.modl
similarity index 100%
rename from modules/MQTT-Transmission-signed (1).modl
rename to modules/MQTTtransmitter.modl