diff --git a/demos/hello_wolf/hello_wolf.cpp b/demos/hello_wolf/hello_wolf.cpp
index 5986a7eeb4f057b36db436584a8905d48c55a85d..93e14f38c41ad1639c09810b4a26631e0ddc61e5 100644
--- a/demos/hello_wolf/hello_wolf.cpp
+++ b/demos/hello_wolf/hello_wolf.cpp
@@ -141,9 +141,8 @@ int main()
     TimeStamp   t(0.0);                          // t : 0.0
     Vector3d    x(0,0,0);
     Matrix3d    P = Matrix3d::Identity() * 0.1;
-    //FrameBasePtr KF1 = problem->setPriorFactor(x, P, 0.5);             // KF1 : (0,0,0)
-    //std::static_pointer_cast<ProcessorMotion>(processor)->setOrigin(KF1);
-    problem->setPriorOptions("factor", 0.5, x, P);
+    FrameBasePtr KF1 = problem->setPriorFactor(x, P, t, 0.5);             // KF1 : (0,0,0)
+    std::static_pointer_cast<ProcessorMotion>(processor)->setOrigin(KF1);
 
     // SELF CALIBRATION ===================================================
 
diff --git a/demos/hello_wolf/hello_wolf_autoconf.cpp b/demos/hello_wolf/hello_wolf_autoconf.cpp
index 5ab1ad1dd20a6b03411ea5cc458bde99b2b1fca8..1b7d7a551b1de4ba0a1fed374a24da716fce29df 100644
--- a/demos/hello_wolf/hello_wolf_autoconf.cpp
+++ b/demos/hello_wolf/hello_wolf_autoconf.cpp
@@ -9,6 +9,7 @@
 // wolf core includes
 #include "core/common/wolf.h"
 #include "core/capture/capture_odom_2d.h"
+#include "core/processor/processor_motion.h"
 #include "core/yaml/parser_yaml.h"
 #include "core/ceres_wrapper/ceres_manager.h"
 
@@ -118,9 +119,11 @@ int main()
     // recover sensor pointers and other stuff for later use (access by sensor name)
     SensorBasePtr sensor_odo    = problem->getSensor("sen odom");
     SensorBasePtr sensor_rb     = problem->getSensor("sen rb");
-    TimeStamp     t             = problem->getTrajectory()->getFrameList().front()->getTimeStamp();
-
 
+    // APPLY PRIOR and SET PROCESSOR ODOM ORIGIN ===================================================
+    TimeStamp     t(0.0);
+    FrameBasePtr KF1 = problem->applyPriorOptions(t);
+    std::static_pointer_cast<ProcessorMotion>(problem->getProcessorIsMotion())->setOrigin(KF1);
 
     // SELF CALIBRATION ===================================================
     // These few lines control whether we calibrate some sensor parameters or not.