diff --git a/circuits/cpp/src/aztec3/circuits/abis/private_circuit_public_inputs.hpp b/circuits/cpp/src/aztec3/circuits/abis/private_circuit_public_inputs.hpp
index 7e7bff8cdd0..b216cd17529 100644
--- a/circuits/cpp/src/aztec3/circuits/abis/private_circuit_public_inputs.hpp
+++ b/circuits/cpp/src/aztec3/circuits/abis/private_circuit_public_inputs.hpp
@@ -274,9 +274,9 @@ template <typename NCT> class OptionalPrivateCircuitPublicInputs {
                    chain_id,
                    version);
 
-    OptionalPrivateCircuitPublicInputs<NCT>() = default;
+    OptionalPrivateCircuitPublicInputs() = default;
 
-    OptionalPrivateCircuitPublicInputs<NCT>(
+    OptionalPrivateCircuitPublicInputs(
         std::optional<CallContext<NCT>> const& call_context,
 
         opt_fr const& args_hash,
diff --git a/circuits/cpp/src/aztec3/circuits/abis/public_circuit_public_inputs.hpp b/circuits/cpp/src/aztec3/circuits/abis/public_circuit_public_inputs.hpp
index 863292fd208..0784704c192 100644
--- a/circuits/cpp/src/aztec3/circuits/abis/public_circuit_public_inputs.hpp
+++ b/circuits/cpp/src/aztec3/circuits/abis/public_circuit_public_inputs.hpp
@@ -45,7 +45,7 @@ template <typename NCT> struct PublicCircuitPublicInputs {
 
     HistoricBlockData<NCT> historic_block_data{};
 
-    address prover_address;
+    address prover_address{};
 
     // for serialization, update with new fields
     MSGPACK_FIELDS(call_context,
diff --git a/circuits/cpp/src/aztec3/circuits/abis/rollup/root/root_rollup_public_inputs.hpp b/circuits/cpp/src/aztec3/circuits/abis/rollup/root/root_rollup_public_inputs.hpp
index a709b025c51..96603192162 100644
--- a/circuits/cpp/src/aztec3/circuits/abis/rollup/root/root_rollup_public_inputs.hpp
+++ b/circuits/cpp/src/aztec3/circuits/abis/rollup/root/root_rollup_public_inputs.hpp
@@ -18,39 +18,39 @@ template <typename NCT> struct RootRollupPublicInputs {
     using AggregationObject = typename NCT::AggregationObject;
 
     // All below are shared between the base and merge rollups
-    AggregationObject end_aggregation_object;
+    AggregationObject end_aggregation_object{};
 
-    GlobalVariables<NCT> global_variables;
+    GlobalVariables<NCT> global_variables{};
 
-    AppendOnlyTreeSnapshot<NCT> start_private_data_tree_snapshot;
-    AppendOnlyTreeSnapshot<NCT> end_private_data_tree_snapshot;
+    AppendOnlyTreeSnapshot<NCT> start_private_data_tree_snapshot{};
+    AppendOnlyTreeSnapshot<NCT> end_private_data_tree_snapshot{};
 
-    AppendOnlyTreeSnapshot<NCT> start_nullifier_tree_snapshot;
-    AppendOnlyTreeSnapshot<NCT> end_nullifier_tree_snapshot;
+    AppendOnlyTreeSnapshot<NCT> start_nullifier_tree_snapshot{};
+    AppendOnlyTreeSnapshot<NCT> end_nullifier_tree_snapshot{};
 
-    AppendOnlyTreeSnapshot<NCT> start_contract_tree_snapshot;
-    AppendOnlyTreeSnapshot<NCT> end_contract_tree_snapshot;
+    AppendOnlyTreeSnapshot<NCT> start_contract_tree_snapshot{};
+    AppendOnlyTreeSnapshot<NCT> end_contract_tree_snapshot{};
 
-    fr start_public_data_tree_root;
-    fr end_public_data_tree_root;
+    fr start_public_data_tree_root{};
+    fr end_public_data_tree_root{};
 
-    AppendOnlyTreeSnapshot<NCT> start_tree_of_historic_private_data_tree_roots_snapshot;
-    AppendOnlyTreeSnapshot<NCT> end_tree_of_historic_private_data_tree_roots_snapshot;
+    AppendOnlyTreeSnapshot<NCT> start_tree_of_historic_private_data_tree_roots_snapshot{};
+    AppendOnlyTreeSnapshot<NCT> end_tree_of_historic_private_data_tree_roots_snapshot{};
 
-    AppendOnlyTreeSnapshot<NCT> start_tree_of_historic_contract_tree_roots_snapshot;
-    AppendOnlyTreeSnapshot<NCT> end_tree_of_historic_contract_tree_roots_snapshot;
+    AppendOnlyTreeSnapshot<NCT> start_tree_of_historic_contract_tree_roots_snapshot{};
+    AppendOnlyTreeSnapshot<NCT> end_tree_of_historic_contract_tree_roots_snapshot{};
 
-    AppendOnlyTreeSnapshot<NCT> start_l1_to_l2_messages_tree_snapshot;
-    AppendOnlyTreeSnapshot<NCT> end_l1_to_l2_messages_tree_snapshot;
+    AppendOnlyTreeSnapshot<NCT> start_l1_to_l2_messages_tree_snapshot{};
+    AppendOnlyTreeSnapshot<NCT> end_l1_to_l2_messages_tree_snapshot{};
 
-    AppendOnlyTreeSnapshot<NCT> start_tree_of_historic_l1_to_l2_messages_tree_roots_snapshot;
-    AppendOnlyTreeSnapshot<NCT> end_tree_of_historic_l1_to_l2_messages_tree_roots_snapshot;
+    AppendOnlyTreeSnapshot<NCT> start_tree_of_historic_l1_to_l2_messages_tree_roots_snapshot{};
+    AppendOnlyTreeSnapshot<NCT> end_tree_of_historic_l1_to_l2_messages_tree_roots_snapshot{};
 
-    AppendOnlyTreeSnapshot<NCT> start_historic_blocks_tree_snapshot;
-    AppendOnlyTreeSnapshot<NCT> end_historic_blocks_tree_snapshot;
+    AppendOnlyTreeSnapshot<NCT> start_historic_blocks_tree_snapshot{};
+    AppendOnlyTreeSnapshot<NCT> end_historic_blocks_tree_snapshot{};
 
-    std::array<fr, NUM_FIELDS_PER_SHA256> calldata_hash;
-    std::array<fr, NUM_FIELDS_PER_SHA256> l1_to_l2_messages_hash;
+    std::array<fr, NUM_FIELDS_PER_SHA256> calldata_hash{};
+    std::array<fr, NUM_FIELDS_PER_SHA256> l1_to_l2_messages_hash{};
 
     // For serialization, update with new fields
     MSGPACK_FIELDS(end_aggregation_object,
diff --git a/circuits/cpp/src/aztec3/circuits/apps/function_execution_context.hpp b/circuits/cpp/src/aztec3/circuits/apps/function_execution_context.hpp
index 766bb47cae9..ad1b597f4ba 100644
--- a/circuits/cpp/src/aztec3/circuits/apps/function_execution_context.hpp
+++ b/circuits/cpp/src/aztec3/circuits/apps/function_execution_context.hpp
@@ -70,7 +70,7 @@ template <typename Builder> class FunctionExecutionContext {
     bool is_finalised = false;
 
   public:
-    FunctionExecutionContext<Builder>(Builder& builder, OracleWrapperInterface<Builder>& oracle)
+    FunctionExecutionContext(Builder& builder, OracleWrapperInterface<Builder>& oracle)
         : builder(builder)
         , oracle(oracle)
         , private_circuit_public_inputs(OptionalPrivateCircuitPublicInputs<CT>::create())
@@ -332,4 +332,4 @@ template <typename Builder> class FunctionExecutionContext {
     }
 };
 
-}  // namespace aztec3::circuits::apps
\ No newline at end of file
+}  // namespace aztec3::circuits::apps
diff --git a/circuits/cpp/src/aztec3/circuits/hash.hpp b/circuits/cpp/src/aztec3/circuits/hash.hpp
index 92f3c1a79f7..4c5141ddf91 100644
--- a/circuits/cpp/src/aztec3/circuits/hash.hpp
+++ b/circuits/cpp/src/aztec3/circuits/hash.hpp
@@ -442,9 +442,9 @@ template <typename NCT> std::array<typename NCT::fr, NUM_FIELDS_PER_SHA256> accu
     // Generate a 512 bit input from right and left 256 bit hashes
     constexpr auto num_bytes = 2 * 32;
     std::array<uint8_t, num_bytes> hash_input_bytes;
-    for (uint8_t i = 0; i < 4; i++) {
+    for (size_t i = 0; i < 4; i++) {
         auto half = hashes[i].to_buffer();
-        for (uint8_t j = 0; j < 16; j++) {
+        for (size_t j = 0; j < 16; j++) {
             hash_input_bytes[i * 16 + j] = half[16 + j];
         }
     }