diff --git a/compose.mailman.yml b/compose.mailman.yml
index d39478c..79188f6 100644
--- a/compose.mailman.yml
+++ b/compose.mailman.yml
@@ -32,4 +32,5 @@ volumes:
 configs:
   postfix_override:
     name: ${STACK_NAME}_postfix_overrides_${POSTFIX_OVERRIDE_VERSION}
-    file: postfix.cf
+    file: postfix.cf.tmpl
+    template_driver: golang
diff --git a/postfix.cf b/postfix.cf.tmpl
similarity index 100%
rename from postfix.cf
rename to postfix.cf.tmpl