diff --git a/Cargo.lock b/Cargo.lock
index 7cef4c57..84b5e1d6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1854,9 +1854,9 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-epoch"
-version = "0.9.20"
+version = "0.9.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2d6914041f254d6e9176c01941b21115dcfb7089e55135a35411081bd106ef3f"
+checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
 dependencies = [
  "crossbeam-utils",
 ]
diff --git a/lee/state_machine/src/lib.rs b/lee/state_machine/src/lib.rs
index 0bd2c901..f8cc034a 100644
--- a/lee/state_machine/src/lib.rs
+++ b/lee/state_machine/src/lib.rs
@@ -30,8 +30,6 @@ pub mod program_deployment_transaction;
 pub mod public_transaction;
 mod signature;
 mod state;
-#[cfg(feature = "test-utils")]
-pub mod test_utils;
 mod validated_state_diff;
 
 mod privacy_preserving_circuit {
diff --git a/lee/state_machine/src/test_utils.rs b/lee/state_machine/src/test_utils.rs
deleted file mode 100644
index f9325ddd..00000000
--- a/lee/state_machine/src/test_utils.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-//! Test-only constructors for otherwise-opaque state types.
-//!
-//! A [`ValidatedStateDiff`] can normally only be produced by the transaction validation
-//! functions, which guarantees it has been checked before any state mutation. These
-//! helpers let downstream crates unit-test *post-execution* validation logic — e.g. the
-//! system-account and bridge guards in `common` — against a hand-built diff, without
-//! running a program in the zkVM.
-
-use std::collections::HashMap;
-
-use crate::{
-    Account, AccountId,
-    validated_state_diff::{StateDiff, ValidatedStateDiff},
-};
-
-/// Builds a [`ValidatedStateDiff`] carrying only the given public-account changes.
-#[must_use]
-pub const fn validated_state_diff_from_public_diff(
-    public_diff: HashMap<AccountId, Account>,
-) -> ValidatedStateDiff {
-    ValidatedStateDiff::new_unchecked(StateDiff {
-        signer_account_ids: Vec::new(),
-        public_diff,
-        new_commitments: Vec::new(),
-        new_nullifiers: Vec::new(),
-        program: None,
-    })
-}
diff --git a/lee/state_machine/src/validated_state_diff.rs b/lee/state_machine/src/validated_state_diff.rs
index 4b754dd9..44a307af 100644
--- a/lee/state_machine/src/validated_state_diff.rs
+++ b/lee/state_machine/src/validated_state_diff.rs
@@ -35,24 +35,10 @@ pub struct StateDiff {
 
 /// The validated output of executing or verifying a transaction, ready to be applied to the state.
 ///
-/// It can only be constructed by the transaction validation functions inside this crate, ensuring
-/// the diff has been checked before any state mutation occurs. Under the `test-utils` feature the
-/// [`crate::test_utils`] module additionally exposes a hand-rolled constructor for unit-testing
-/// downstream validation logic; that feature must never be enabled in a production build.
+/// Can only be constructed by the transaction validation functions inside this crate, ensuring the
+/// diff has been checked before any state mutation occurs.
 pub struct ValidatedStateDiff(StateDiff);
 
-#[cfg(feature = "test-utils")]
-impl ValidatedStateDiff {
-    /// Test-only constructor that wraps an already-built [`StateDiff`] **without validating it**.
-    ///
-    /// Kept in this module so the wrapped field can stay private: in a normal build (feature off)
-    /// the only ways to obtain a `ValidatedStateDiff` remain the `from_*_transaction` validators.
-    #[must_use]
-    pub const fn new_unchecked(state_diff: StateDiff) -> Self {
-        Self(state_diff)
-    }
-}
-
 impl ValidatedStateDiff {
     pub fn from_public_transaction(
         tx: &PublicTransaction,
diff --git a/lez/common/Cargo.toml b/lez/common/Cargo.toml
index 7582e885..8b2aa322 100644
--- a/lez/common/Cargo.toml
+++ b/lez/common/Cargo.toml
@@ -25,6 +25,3 @@ log.workspace = true
 hex.workspace = true
 borsh.workspace = true
 logos-blockchain-common-http-client.workspace = true
-
-[dev-dependencies]
-lee = { workspace = true, features = ["test-utils"] }
diff --git a/lez/common/src/test_utils.rs b/lez/common/src/test_utils.rs
index 4a9ab992..7afda3dd 100644
--- a/lez/common/src/test_utils.rs
+++ b/lez/common/src/test_utils.rs
@@ -1,12 +1,4 @@
-// Backs the hand-built state/diff helpers below, which are compiled only for `common`'s own
-// unit tests. They rely on `lee::test_utils`, gated behind `lee`'s `test-utils` feature and
-// enabled here via dev-dependencies, so it never reaches a production build.
-#[cfg(test)]
-use std::collections::HashMap;
-
 use lee::AccountId;
-#[cfg(test)]
-use lee::{Account, PrivateKey, PublicKey, V03State, ValidatedStateDiff};
 
 use crate::{
     HashType,
@@ -21,33 +13,6 @@ pub fn sequencer_sign_key_for_testing() -> lee::PrivateKey {
     lee::PrivateKey::try_new([37; 32]).unwrap()
 }
 
-/// A syntactically valid `Public` transaction. Its contents are irrelevant to the
-/// bridge guard, which only branches on the transaction *variant* and the diff.
-#[cfg(test)]
-#[must_use]
-pub fn any_public_transaction() -> LeeTransaction {
-    let sender_key = PrivateKey::try_new([9_u8; 32]).expect("valid key");
-    let sender_id = AccountId::from(&PublicKey::new_from_private_key(&sender_key));
-    let recipient_key = PrivateKey::try_new([8_u8; 32]).expect("valid key");
-    let recipient_id = AccountId::from(&PublicKey::new_from_private_key(&recipient_key));
-    create_transaction_native_token_transfer(sender_id, 0, recipient_id, 1, &sender_key)
-}
-
-/// Builds a state whose only entry is `account_id` (set to `pre`) and a single-entry diff
-/// that maps `account_id` to `post`, so the validation guards can be exercised in isolation.
-#[cfg(test)]
-#[must_use]
-pub fn state_and_diff(
-    account_id: AccountId,
-    pre: Account,
-    post: Account,
-) -> (V03State, ValidatedStateDiff) {
-    let state = V03State::new().with_public_accounts([(account_id, pre)]);
-    let diff =
-        lee::test_utils::validated_state_diff_from_public_diff(HashMap::from([(account_id, post)]));
-    (state, diff)
-}
-
 // Dummy producers
 
 /// Produce dummy block with provided transactions + clock transaction an the end.
diff --git a/lez/common/src/transaction.rs b/lez/common/src/transaction.rs
index 64725738..b5aee648 100644
--- a/lez/common/src/transaction.rs
+++ b/lez/common/src/transaction.rs
@@ -260,112 +260,9 @@ fn validate_doesnt_modify_account(
 
 #[cfg(test)]
 mod tests {
-    use lee::{Account, AccountId, PrivateKey, PublicKey, V03State};
-    use lee_core::account::Nonce;
+    use lee::{AccountId, PrivateKey, PublicKey, V03State};
 
-    use super::validate_doesnt_modify_account;
-    use crate::test_utils::{
-        any_public_transaction, create_transaction_native_token_transfer, state_and_diff,
-    };
-
-    #[test]
-    fn bridge_guard_allows_balance_only_increase() {
-        // A diff that *only* increases the bridge balance (the legitimate deposit shape)
-        // must be accepted.
-        let bridge_id = system_accounts::bridge_account_id();
-        let pre = Account {
-            balance: 500,
-            nonce: Nonce(7),
-            ..Account::default()
-        };
-        let post = Account {
-            balance: 600,
-            ..pre.clone()
-        };
-        let (state, diff) = state_and_diff(bridge_id, pre, post);
-
-        let tx = any_public_transaction();
-        assert!(
-            tx.validate_bridge_account_modification(&state, &diff)
-                .is_ok(),
-            "a balance-only increase of the bridge account must be allowed",
-        );
-    }
-
-    #[test]
-    fn bridge_guard_rejects_data_modification_even_when_balance_increases() {
-        // A diff that changes the bridge account's data (here: the nonce) while *also*
-        // increasing its balance must be rejected.
-        let bridge_id = system_accounts::bridge_account_id();
-        let pre = Account {
-            balance: 500,
-            nonce: Nonce(7),
-            ..Account::default()
-        };
-        let post = Account {
-            balance: 600,
-            nonce: Nonce(8),
-            ..pre.clone()
-        };
-        let (state, diff) = state_and_diff(bridge_id, pre, post);
-
-        let tx = any_public_transaction();
-        assert!(
-            tx.validate_bridge_account_modification(&state, &diff)
-                .is_err(),
-            "modifying bridge account data must be rejected even if the balance increases",
-        );
-    }
-
-    #[test]
-    fn bridge_guard_rejects_zero_value_deposit() {
-        // A diff that touches the bridge account without *strictly* increasing its balance
-        // must be rejected — a zero-value deposit is not a real credit.
-        let bridge_id = system_accounts::bridge_account_id();
-        let pre = Account {
-            balance: 500,
-            nonce: Nonce(7),
-            ..Account::default()
-        };
-        let post = pre.clone();
-        let (state, diff) = state_and_diff(bridge_id, pre, post);
-
-        let tx = any_public_transaction();
-        assert!(
-            tx.validate_bridge_account_modification(&state, &diff)
-                .is_err(),
-            "a bridge diff that does not strictly increase the balance must be rejected",
-        );
-    }
-
-    #[test]
-    fn validate_doesnt_modify_account_flags_a_changed_account() {
-        // Directly exercise the system-account guard with a diff that genuinely changes a
-        // clock account, then with one that leaves it untouched. The inverted comparison would
-        // treat a changed account as unchanged and wave it through (and would flag an *unchanged*
-        // account instead).
-        let clock_id = system_accounts::clock_account_ids()[0];
-        let pre = Account {
-            balance: 1_000,
-            ..Account::default()
-        };
-
-        let changed = Account {
-            balance: 2_000,
-            ..Account::default()
-        };
-        let (state, diff) = state_and_diff(clock_id, pre.clone(), changed);
-        assert!(
-            validate_doesnt_modify_account(&state, &diff, clock_id).is_err(),
-            "a diff that changes a system account must be rejected",
-        );
-
-        let (unchanged_state, unchanged_diff) = state_and_diff(clock_id, pre.clone(), pre);
-        assert!(
-            validate_doesnt_modify_account(&unchanged_state, &unchanged_diff, clock_id).is_ok(),
-            "a diff that leaves a system account unchanged must be accepted",
-        );
-    }
+    use crate::test_utils::create_transaction_native_token_transfer;
 
     #[test]
     fn system_account_ids_are_distinct_and_non_default() {