diff --git a/src/qiskit_qec/circuits/intern/arctools.cpp b/src/qiskit_qec/circuits/intern/arctools.cpp
index 642ac96b..d14ec7e5 100644
--- a/src/qiskit_qec/circuits/intern/arctools.cpp
+++ b/src/qiskit_qec/circuits/intern/arctools.cpp
@@ -9,7 +9,7 @@ bool is_cluster_neutral(
         return nodes.size()%2==0;
     } else {
         std::vector<int> output = check_nodes(nodes, ignore_extra_logicals, minimal, cycle_dict, link_graph, link_neighbors, z_logicals);
-        return (output[0]==1) and (output.size()==0);
+        return (output[0]==1) and (output.size()==2);
     }
 
 };
diff --git a/src/qiskit_qec/circuits/repetition_code.py b/src/qiskit_qec/circuits/repetition_code.py
index 39cc5cf4..c28c3871 100644
--- a/src/qiskit_qec/circuits/repetition_code.py
+++ b/src/qiskit_qec/circuits/repetition_code.py
@@ -1358,7 +1358,7 @@ def check_nodes(self, nodes, ignore_extra_logical=False, minimal=False, cpp=True
 
             return neutral, flipped_logical_nodes, num_errors
 
-    def is_cluster_neutral(self, atypical_nodes: dict, cpp=False):
+    def is_cluster_neutral(self, atypical_nodes: dict, cpp=True):
         """
         Determines whether or not the cluster is neutral, meaning that one or more
         errors could have caused the set of atypical nodes (syndrome changes) passed