diff --git a/org/qmckl_local_energy.org b/org/qmckl_local_energy.org
index 1a1cacc..7e9e392 100644
--- a/org/qmckl_local_energy.org
+++ b/org/qmckl_local_energy.org
@@ -1645,7 +1645,7 @@ end function qmckl_compute_drift_vector_f
      #+begin_src c :tangle (eval c_test) :exports none
 // Calculate the Drift vector
 
-double drift_vector[walk_num][3];
+double drift_vector[walk_num][elec_num][3];
 
 rc = qmckl_get_drift_vector(context, &(drift_vector[0][0]));
 assert (rc == QMCKL_SUCCESS);