diff --git a/arbor/cv_policy.cpp b/arbor/cv_policy.cpp
index ccda7661f..e79db9dd6 100644
--- a/arbor/cv_policy.cpp
+++ b/arbor/cv_policy.cpp
@@ -40,6 +40,8 @@ struct cvp_cv_policy_plus {
         return os;
     }
 
+    cvp_cv_policy_plus(const cv_policy& lhs, const cv_policy& rhs): lhs_{lhs}, rhs_(rhs) {}
+
     cv_policy lhs_, rhs_;
 };
 
diff --git a/python/example/probe_lfpykit.py b/python/example/probe_lfpykit.py
index 4bd106132..45a0ba5a9 100644
--- a/python/example/probe_lfpykit.py
+++ b/python/example/probe_lfpykit.py
@@ -91,7 +91,7 @@ def probes(self, _):
 )
 
 # use a fixed 3 CVs per branch
-cvp = A.cv_policy(A.cv_policy_fixed_per_branch(3))
+cvp = A.cv_policy_fixed_per_branch(3)
 
 # place_pwlin can be queried with region/locset expressions to obtain
 # geometrical objects, like points and segments, essentially recovering