diff --git a/demos/hello_wolf/yaml/hello_wolf_config.yaml b/demos/hello_wolf/yaml/hello_wolf_config.yaml
index 90e1c1616c1d32955bc50ccf04eae73e0ef01159..f2e4f8db31f97ef8059b4d59483a747456e6d19c 100644
--- a/demos/hello_wolf/yaml/hello_wolf_config.yaml
+++ b/demos/hello_wolf/yaml/hello_wolf_config.yaml
@@ -11,8 +11,14 @@ config:
     dimension:            2               # space is 2d
     prior:
       mode:               "factor"
-      state:              [0,0,0]
-      cov:                [[3,3],.01,0,0,0,.01,0,0,0,.01]
+      # state:              [0,0,0]
+      $state:
+        P: [0,0]
+        O: [0]
+      # cov:                [[3,3],.01,0,0,0,.01,0,0,0,.01]
+      $sigma:
+        P: [0.31, 0.31]
+        O: [0.31]
       time_tolerance:     0.1
     
   sensors: