diff --git a/gradle-plugins/docker-compose/src/main/kotlin/dev/adamko/geedeecee/tasks/DockerEnvUpdateTask.kt b/gradle-plugins/docker-compose/src/main/kotlin/dev/adamko/geedeecee/tasks/DockerEnvUpdateTask.kt
index 13332e5..6fddbd6 100644
--- a/gradle-plugins/docker-compose/src/main/kotlin/dev/adamko/geedeecee/tasks/DockerEnvUpdateTask.kt
+++ b/gradle-plugins/docker-compose/src/main/kotlin/dev/adamko/geedeecee/tasks/DockerEnvUpdateTask.kt
@@ -25,6 +25,7 @@ abstract class DockerEnvUpdateTask @Inject constructor(
 ) : DefaultTask() {
 
   @get:Input
+  @get:Optional
   abstract val envProperties: MapProperty<String, String>
 
   @get:Input
@@ -50,10 +51,11 @@ abstract class DockerEnvUpdateTask @Inject constructor(
     val comment: String = comment.orNull
       ?: " Do not edit manually. This file was created with task '$name'"
 
+    val envProperties = envProperties.getOrElse(emptyMap())
 
     dotEnvFile.writer(charset).use { writer ->
       val properties = Properties()
-      properties.putAll(envProperties.get())
+      properties.putAll(envProperties)
       properties.store(writer, comment)
     }
 
diff --git a/modules/infra-factorio-server/build.gradle.kts b/modules/infra-factorio-server/build.gradle.kts
index ab89991..2093c80 100644
--- a/modules/infra-factorio-server/build.gradle.kts
+++ b/modules/infra-factorio-server/build.gradle.kts
@@ -61,13 +61,15 @@ tasks.dockerComposeUp {
 }
 
 
-val kafkatorioServerToken: String by project
+val kafkatorioServerToken: String? by project
 
 
 tasks.dockerComposeEnvUpdate {
   envProperties {
     put("FACTORIO_VERSION", libs.versions.factorio)
-    put("KAFKATORIO_TOKEN", kafkatorioServerToken)
+    kafkatorioServerToken?.let { token ->
+      put("KAFKATORIO_TOKEN", token)
+    }
   }
 }