diff --git a/awx/main/models/inventory.py b/awx/main/models/inventory.py
index 7d6c350274..7d9069e4f0 100644
--- a/awx/main/models/inventory.py
+++ b/awx/main/models/inventory.py
@@ -1163,13 +1163,6 @@ class InventorySource(UnifiedJobTemplate, InventorySourceOptions, CustomVirtualE
         source_vars = dict(self.source_vars_dict) # make a copy
         if injector and self.source_vars_dict.get('plugin', '') != injector.get_proper_name():
             source_vars['plugin'] = injector.get_proper_name()
-        elif not injector:
-            source_vars = dict(self.source_vars_dict) # make a copy
-            collection_pattern = re.compile("^(.+)\.(.+)\.(.+)$") # noqa
-            if 'plugin' not in source_vars:
-                raise ValidationError(_("plugin: must be present and of the form namespace.collection.inv_plugin"))
-            elif not bool(collection_pattern.match(source_vars['plugin'])):
-                raise ValidationError(_("plugin: must be of the form namespace.collection.inv_plugin"))
         return json.dumps(source_vars)
 
     '''
diff --git a/awx/main/tests/functional/api/test_inventory.py b/awx/main/tests/functional/api/test_inventory.py
index 8eda9cddd0..a04a68c9bb 100644
--- a/awx/main/tests/functional/api/test_inventory.py
+++ b/awx/main/tests/functional/api/test_inventory.py
@@ -471,7 +471,10 @@ def test_inventory_source_vars_source_plugin_ok(post, inventory, admin_user, sou
 
 @pytest.mark.django_db
 @pytest.mark.parametrize('source_var_actual,description', [
-    ({'plugin': 'namespace.collection.script'}, 'valid scm user plugin'),
+    ({'plugin': 'namespace.collection.script'}, 'scm source type source_vars are ignored valid'),
+    ({'plugin': 'namespace.collection.script'}, 'scm source type source_vars are ignored invalid'),
+    ({'plugin': ''}, 'scm source type source_vars are ignored blank'),
+    ({}, 'scm source type source_vars are ignored non-existent'),
 ])
 def test_inventory_source_vars_source_plugin_scm_ok(post, inventory, admin_user, project, source_var_actual, description):
     r = post(reverse('api:inventory_source_list'),
@@ -485,27 +488,6 @@ def test_inventory_source_vars_source_plugin_scm_ok(post, inventory, admin_user,
     assert r.data['source_vars'] == json.dumps(source_var_actual)
 
 
-@pytest.mark.django_db
-@pytest.mark.parametrize('source_var_actual,err_msg,description', [
-    ({'foo': 'bar'}, 'plugin: must be present and of the form namespace.collection.inv_plugin', 'no plugin line'),
-    ({'plugin': ''}, 'plugin: must be of the form namespace.collection.inv_plugin', 'blank plugin line'),
-    ({'plugin': '.'}, 'plugin: must be of the form namespace.collection.inv_plugin', 'missing namespace, collection name, and inventory plugin'),
-    ({'plugin': 'a.'}, 'plugin: must be of the form namespace.collection.inv_plugin', 'missing collection name and inventory plugin'),
-    ({'plugin': 'a.b'}, 'plugin: must be of the form namespace.collection.inv_plugin', 'missing inventory plugin'),
-    ({'plugin': 'a.b.'}, 'plugin: must be of the form namespace.collection.inv_plugin', 'missing inventory plugin'),
-])
-def test_inventory_source_vars_source_plugin_scm_invalid(post, inventory, admin_user, project, source_var_actual, err_msg, description):
-    r = post(reverse('api:inventory_source_list'),
-             {'name': 'new inv src',
-              'source_vars': json.dumps(source_var_actual),
-              'inventory': inventory.pk,
-              'source': 'scm',
-              'source_project': project.id,},
-             admin_user, expect=400)
-
-    assert err_msg in r.data['source_vars'][0]
-
-
 @pytest.mark.django_db
 @pytest.mark.parametrize('role,expect', [
     ('admin_role', 200),