diff --git a/library/system/debconf b/library/system/debconf
index b05b05d176..1b48e04156 100644
--- a/library/system/debconf
+++ b/library/system/debconf
@@ -147,7 +147,7 @@ def main():
             if rc:
                 module.fail_json(msg=e)
 	curr = { question: value }
-	prev = (question: prev[question])
+	prev = {question: prev[question]}
 
         module.exit_json(changed=changed, msg=msg, current=curr, previous=prev)