diff --git a/ecs-task.cfndsl.rb b/ecs-task.cfndsl.rb
index 7d49d0e..caa2555 100644
--- a/ecs-task.cfndsl.rb
+++ b/ecs-task.cfndsl.rb
@@ -38,7 +38,7 @@
       # create main definition
       task_def =  {
         Name: name,
-        Image: FnSub("#{image_repo}/#{image_name}:#{image_tag}"),
+        Image: FnSub("#{image_repo}/#{image_name}\\:#{image_tag}"),
         LogConfiguration: {
           LogDriver: 'awslogs',
           Options: {