diff --git a/tasks/main.yml b/tasks/main.yml
index aebe114..f9ccc70 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -97,9 +97,9 @@
       POSTSCREEN_DNSBL_ACTION:
         "{{ postfix_postscreen_dnsbl_action }}"
       POSTSCREEN_DNSBL_THRESHOLD:
-        "{{ postfix_postscreen_dnsbl_threshold }}"
+        "{{ postfix_postscreen_dnsbl_threshold | string}}"
       POSTSCREEN_DNSBL_WHITELIST_THRESHOLD:
-        "{{ postfix_postscreen_dnsbl_whitelist_threshold }}"
+        "{{ postfix_postscreen_dnsbl_whitelist_threshold | string }}"
       POSTSCREEN_GREET_ACTION:
         "{{ postfix_postscreen_greet_action }}"