diff --git a/defaults/main.yml b/defaults/main.yml
index e1cec18..d0fc191 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -22,6 +22,10 @@ postfix_local_networks: []
 # domain-specific configuration
 postfix_domain_config: {}
 
+# LOOKUP TABLES ---------------------------------------------------------------
+
+postfix_lookup_provider: file
+
 # LDAP ------------------------------------------------------------------------
 
 # Default LDAP connection parameters