diff --git a/evm/src/cpu/kernel/asm/core/transfer.asm b/evm/src/cpu/kernel/asm/core/transfer.asm
index 05582e6e..8ae2d854 100644
--- a/evm/src/cpu/kernel/asm/core/transfer.asm
+++ b/evm/src/cpu/kernel/asm/core/transfer.asm
@@ -38,6 +38,7 @@ global transfer_eth_failure:
 // Returns 0 on success, or 1 if addr has insufficient balance. Panics if addr isn't found in the trie.
 // Pre stack: addr, amount, retdest
 // Post stack: status (0 indicates success)
+// TODO: Should it be copy-on-write (with make_account_copy) instead of mutating the trie?
 global deduct_eth:
     // stack: addr, amount, retdest
     %mpt_read_state_trie
@@ -73,7 +74,7 @@ global deduct_eth_insufficient_balance:
 
 // Pre stack: addr, amount, redest
 // Post stack: (empty)
-// TODO: Should it be copy-on-write instead of mutating the trie?
+// TODO: Should it be copy-on-write (with make_account_copy) instead of mutating the trie?
 global add_eth:
     // stack: addr, amount, retdest
     DUP1 %mpt_read_state_trie
diff --git a/evm/src/cpu/kernel/asm/mpt/accounts.asm b/evm/src/cpu/kernel/asm/mpt/accounts.asm
index 08291048..050dbb41 100644
--- a/evm/src/cpu/kernel/asm/mpt/accounts.asm
+++ b/evm/src/cpu/kernel/asm/mpt/accounts.asm
@@ -38,8 +38,8 @@ global make_account_copy:
 
     DUP2                %mload_trie_data %append_to_trie_data
     DUP2  %add_const(1) %mload_trie_data %append_to_trie_data
-    DUP2  %add_const(3) %mload_trie_data %append_to_trie_data
-    SWAP1 %add_const(4) %mload_trie_data %append_to_trie_data
+    DUP2  %add_const(2) %mload_trie_data %append_to_trie_data
+    SWAP1 %add_const(3) %mload_trie_data %append_to_trie_data
 
     // stack: new_account_ptr, retdest
     SWAP1
diff --git a/evm/src/cpu/kernel/constants/trie_type.rs b/evm/src/cpu/kernel/constants/trie_type.rs
index 30f4802b..fc71c1f4 100644
--- a/evm/src/cpu/kernel/constants/trie_type.rs
+++ b/evm/src/cpu/kernel/constants/trie_type.rs
@@ -1,6 +1,6 @@
 use eth_trie_utils::partial_trie::PartialTrie;
 
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub(crate) enum PartialTrieType {
     Empty = 0,
     Hash = 1,
diff --git a/evm/src/generation/mod.rs b/evm/src/generation/mod.rs
index aa17b9c9..2c786d8f 100644
--- a/evm/src/generation/mod.rs
+++ b/evm/src/generation/mod.rs
@@ -123,6 +123,11 @@ pub(crate) fn generate_traces<F: RichField + Extendable<D>, const D: usize>(
 
     timed!(timing, "simulate CPU", simulate_cpu(&mut state)?);
 
+    assert!(
+        state.mpt_prover_inputs.is_empty(),
+        "All MPT data should have been consumed"
+    );
+
     log::info!(
         "Trace lengths (before padding): {:?}",
         state.traces.checkpoint()
diff --git a/evm/src/generation/outputs.rs b/evm/src/generation/outputs.rs
index a197b1b6..b6da3576 100644
--- a/evm/src/generation/outputs.rs
+++ b/evm/src/generation/outputs.rs
@@ -78,7 +78,7 @@ fn account_trie_record_to_output<F: Field>(
         .inputs
         .contract_code
         .get(&account.code_hash)
-        .expect("Code not found")
+        .unwrap_or_else(|| panic!("Code not found: {:?}", account.code_hash))
         .clone();
 
     AccountOutput {
diff --git a/evm/src/generation/trie_extractor.rs b/evm/src/generation/trie_extractor.rs
index a7f01c97..66174419 100644
--- a/evm/src/generation/trie_extractor.rs
+++ b/evm/src/generation/trie_extractor.rs
@@ -10,6 +10,7 @@ use crate::memory::segments::Segment;
 use crate::witness::memory::{MemoryAddress, MemoryState};
 
 /// Account data as it's stored in the state trie, with a pointer to the storage trie.
+#[derive(Debug)]
 pub(crate) struct AccountTrieRecord {
     pub(crate) nonce: u64,
     pub(crate) balance: U256,