diff --git a/src/stim/stabilizers/pauli_string_ref.inl b/src/stim/stabilizers/pauli_string_ref.inl
index 5d8a9599..943b6763 100644
--- a/src/stim/stabilizers/pauli_string_ref.inl
+++ b/src/stim/stabilizers/pauli_string_ref.inl
@@ -883,9 +883,9 @@ template <bool reverse_order>
 void PauliStringRef<W>::do_ZCX(const CircuitInstruction &inst) {
     const auto &targets = inst.targets;
     assert((targets.size() & 1) == 0);
-    for (size_t k = 0; k < inst.targets.size(); k += 2) {
-        size_t k2 = reverse_order ? inst.targets.size() - 2 - k : k;
-        size_t q1 = inst.targets[k2].data, q2 = inst.targets[k2 + 1].data;
+    for (size_t k = 0; k < targets.size(); k += 2) {
+        size_t k2 = reverse_order ? targets.size() - 2 - k : k;
+        size_t q1 = targets[k2].data, q2 = targets[k2 + 1].data;
         do_single_cx(inst, q1, q2);
     }
 }
@@ -895,9 +895,9 @@ template <bool reverse_order>
 void PauliStringRef<W>::do_ZCY(const CircuitInstruction &inst) {
     const auto &targets = inst.targets;
     assert((targets.size() & 1) == 0);
-    for (size_t k = 0; k < inst.targets.size(); k += 2) {
-        size_t k2 = reverse_order ? inst.targets.size() - 2 - k : k;
-        size_t q1 = inst.targets[k2].data, q2 = inst.targets[k2 + 1].data;
+    for (size_t k = 0; k < targets.size(); k += 2) {
+        size_t k2 = reverse_order ? targets.size() - 2 - k : k;
+        size_t q1 = targets[k2].data, q2 = targets[k2 + 1].data;
         do_single_cy(inst, q1, q2);
     }
 }
@@ -916,9 +916,9 @@ template <bool reverse_order>
 void PauliStringRef<W>::do_SWAP(const CircuitInstruction &inst) {
     const auto &targets = inst.targets;
     assert((targets.size() & 1) == 0);
-    for (size_t k = 0; k < inst.targets.size(); k += 2) {
-        size_t k2 = reverse_order ? inst.targets.size() - 2 - k : k;
-        size_t q1 = inst.targets[k2].data, q2 = inst.targets[k2 + 1].data;
+    for (size_t k = 0; k < targets.size(); k += 2) {
+        size_t k2 = reverse_order ? targets.size() - 2 - k : k;
+        size_t q1 = targets[k2].data, q2 = targets[k2 + 1].data;
         zs[q1].swap_with(zs[q2]);
         xs[q1].swap_with(xs[q2]);
     }
diff --git a/src/stim/util_top/dem_to_matrix.cc b/src/stim/util_top/dem_to_matrix.cc
index f057ad59..6544968b 100644
--- a/src/stim/util_top/dem_to_matrix.cc
+++ b/src/stim/util_top/dem_to_matrix.cc
@@ -15,7 +15,7 @@ std::map<SparseXorVec<DemTarget>, double> stim::dem_to_map(const DetectorErrorMo
                 buf.sorted_items.push_back(t);
             }
         }
-        size_t kept = xor_sort<DemTarget>(buf);
+        size_t kept = xor_sort<DemTarget>(buf.sorted_items);
         buf.sorted_items.resize(kept);
         auto q = instruction.arg_data[0];
         auto &p = result[buf];