diff --git a/docker-compose.yml b/docker-compose.yml
index 2d5f2d3..1e8ea5a 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -18,7 +18,7 @@ services:
       POSTGRES_USER: ${POSTGRES_USER:-nodeledge}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?set POSTGRES_PASSWORD in the stack environment}
       POSTGRES_DB: ${POSTGRES_DB:-nodeledge}
-      TZ=${TZ:-Europe/Stockholm}
+      TZ: ${TZ:-Europe/Stockholm}
     volumes:
       - db_data:/var/lib/postgresql/data
       # Creates the mqtt_messages table on the first database start only.
@@ -55,7 +55,7 @@ services:
       # Comma-separated payload keys searched for a device timestamp.
       PAYLOAD_TIME_KEYS: ${PAYLOAD_TIME_KEYS:-timestamp,time,ts}
       LOG_LEVEL: ${LOG_LEVEL:-INFO}
-      TZ=${TZ:-Europe/Stockholm}
+      TZ: ${TZ:-Europe/Stockholm}
     volumes:
       # IMEI -> device name mapping, see configs/listener/imei_map.json
       - ./configs/listener:/app/config:ro
@@ -83,7 +83,7 @@ services:
       IMEI_MAP_FILE: /app/config-listener/imei_map.json
       API_MAX_LIMIT: ${API_MAX_LIMIT:-10000}
       LOG_LEVEL: ${LOG_LEVEL:-INFO}
-      TZ=${TZ:-Europe/Stockholm}
+      TZ: ${TZ:-Europe/Stockholm}
     volumes:
       # app tokens for API auth + the listener's IMEI map; mounted rw so the
       # /configs endpoints can update them (writes are atomic)