diff --git a/ecs-task.cfndsl.rb b/ecs-task.cfndsl.rb
index 94cf39e..5e71d28 100644
--- a/ecs-task.cfndsl.rb
+++ b/ecs-task.cfndsl.rb
@@ -10,7 +10,7 @@
 
     tags = external_parameters.fetch(:tags, [])
     tags.each do |key,value|
-      task_tags << { Key: key, Value: value }
+      task_tags << { Key: FnSub(key), Value: FnSub(value) }
     end
 
     log_retention = external_parameters.fetch(:log_retention, 7)