diff --git a/irrd/conf/default_config.yaml b/irrd/conf/default_config.yaml
index a99d7d22e..748c615c3 100644
--- a/irrd/conf/default_config.yaml
+++ b/irrd/conf/default_config.yaml
@@ -45,6 +45,11 @@ irrd:
     auth:
         gnupg_keyring: null
         authenticate_parents_route_creation: true
+        set_creation:
+            COMMON:
+                prefix_required: true
+                autnum_authentication: opportunistic
+
     email:
         footer: ''
         notification_header: |
diff --git a/irrd/updates/parser_state.py b/irrd/updates/parser_state.py
index 7566080b6..acaf918cf 100644
--- a/irrd/updates/parser_state.py
+++ b/irrd/updates/parser_state.py
@@ -34,6 +34,4 @@ def for_set_name(set_name: str):
         setting = get_setting(f'auth.set_creation.{set_name}.autnum_authentication')
         if not setting:
             setting = get_setting(f'auth.set_creation.{AUTH_SET_CREATION_COMMON_KEY}.autnum_authentication')
-        if not setting:
-            return RPSLSetAutnumAuthenticationMode.DISABLED
         return getattr(RPSLSetAutnumAuthenticationMode, setting.upper())
diff --git a/irrd/updates/tests/test_validators.py b/irrd/updates/tests/test_validators.py
index d203f8ce9..c27880fa1 100644
--- a/irrd/updates/tests/test_validators.py
+++ b/irrd/updates/tests/test_validators.py
@@ -455,8 +455,7 @@ def test_as_set_autnum_disabled(self, prepare_mocks, config_override):
             ['rpsl_pks', ({'TEST-MNT'},), {}],
         ]
 
-    def test_as_set_autnum_opportunistic_exists(self, prepare_mocks, config_override):
-        config_override({'auth': {'set_creation': {'as-set': {'autnum_authentication': 'opportunistic'}}}})
+    def test_as_set_autnum_opportunistic_exists_default(self, prepare_mocks, config_override):
         validator, mock_dq, mock_dh = prepare_mocks
         as_set = rpsl_object_from_text(SAMPLE_AS_SET)
         assert as_set.clean_for_create()  # fill pk_asn_segment
@@ -506,11 +505,6 @@ def test_as_set_autnum_opportunistic_exists(self, prepare_mocks, config_override
         result = validator.process_auth(as_set, None)
         assert result.is_valid()
 
-        # Default is disabled
-        config_override({})
-        result = validator.process_auth(as_set, None)
-        assert result.is_valid()
-
     def test_as_set_autnum_opportunistic_does_not_exist(self, prepare_mocks, config_override):
         config_override({'auth': {'set_creation': {
             AUTH_SET_CREATION_COMMON_KEY: {'autnum_authentication': 'opportunistic'}