diff --git a/Dockerfile.alpine b/Dockerfile.alpine
index 0930dd658..fd47771a7 100644
--- a/Dockerfile.alpine
+++ b/Dockerfile.alpine
@@ -1,6 +1,6 @@
 FROM alpine:3.21
 
-ENV TRACCAR_VERSION 6.6
+ENV TRACCAR_VERSION=6.6
 
 WORKDIR /opt/traccar
 
diff --git a/Dockerfile.debian b/Dockerfile.debian
index 9ecc3a22c..a2e157694 100644
--- a/Dockerfile.debian
+++ b/Dockerfile.debian
@@ -1,6 +1,6 @@
 FROM debian:12-slim
 
-ENV TRACCAR_VERSION 6.6
+ENV TRACCAR_VERSION=6.6
 
 WORKDIR /opt/traccar
 
diff --git a/Dockerfile.ubuntu b/Dockerfile.ubuntu
index 9b8908011..49e97c860 100644
--- a/Dockerfile.ubuntu
+++ b/Dockerfile.ubuntu
@@ -1,6 +1,6 @@
 FROM ubuntu:24.04
 
-ENV TRACCAR_VERSION 6.6
+ENV TRACCAR_VERSION=6.6
 
 WORKDIR /opt/traccar