diff --git a/docker/pulsar/scripts/gen-yml-from-env.py b/docker/pulsar/scripts/gen-yml-from-env.py
index 1aa16b47b4430025855f6d69c5571619def94d4e..6bddcdf938add1a6959b48f06dece3562bf78c5a 100755
--- a/docker/pulsar/scripts/gen-yml-from-env.py
+++ b/docker/pulsar/scripts/gen-yml-from-env.py
@@ -46,7 +46,7 @@ if len(sys.argv) < 2:
 conf_files = sys.argv[1:]
 
 for conf_filename in conf_files:
-    conf = yaml.load(open(conf_filename))
+    conf = yaml.load(open(conf_filename), Loader=yaml.FullLoader)
 
     # update the config
     modified = False