diff --git a/awx/main/tests/unit/test_tasks.py b/awx/main/tests/unit/test_tasks.py
index ba8c7dde75..d83dea71dd 100644
--- a/awx/main/tests/unit/test_tasks.py
+++ b/awx/main/tests/unit/test_tasks.py
@@ -1757,7 +1757,7 @@ class TestInventoryUpdateCredentials(TestJobExecution):
             self.instance.credential, 'password'
         )
 
-        self.instance.source_vars['prefer_ipv4'] = True
+        self.instance.source_vars = '{"prefer_ipv4": True}'
 
         def run_pexpect_side_effect(*args, **kwargs):
             args, cwd, env, stdout = args
@@ -1767,7 +1767,7 @@ class TestInventoryUpdateCredentials(TestJobExecution):
             assert config.get('cloudforms', 'username') == 'bob'
             assert config.get('cloudforms', 'password') == 'secret'
             assert config.get('cloudforms', 'ssl_verify') == 'false'
-            assert config.get('cloudforms', 'prefer_ipv4') == 'true'
+            assert config.get('cloudforms', 'prefer_ipv4') == 'True'
 
             cache_path = config.get('cache', 'path')
             assert cache_path.startswith(env['AWX_PRIVATE_DATA_DIR'])