--- a/testsuite/testsuite_support/polyfill.py	2020-03-26 20:43:40.861154768 +0100
+++ b/testsuite/testsuite_support/polyfill.py	2020-03-26 20:44:07.874675123 +0100
@@ -376,7 +376,7 @@
         # First load data provided by this testcase
         try:
             with open(os.path.join(test_dir, 'test.yaml'), 'r') as f:
-                test_data = yaml.load(f)
+                test_data = yaml.safe_load(f)
         except (IOError, yaml.error.YAMLError) as exc:
             status = 'PROBLEM'
             message = 'Invalid test.yaml: {}'.format(exc)