diff --git a/crates/blockifier/src/transaction.rs b/crates/blockifier/src/transaction.rs
index 99a227c1de..78ee679cae 100644
--- a/crates/blockifier/src/transaction.rs
+++ b/crates/blockifier/src/transaction.rs
@@ -1,5 +1,7 @@
 pub mod account_transaction;
 pub mod constants;
+#[cfg(test)]
+pub mod error_format_test;
 pub mod errors;
 pub mod objects;
 #[cfg(any(feature = "testing", test))]
diff --git a/crates/blockifier/src/transaction/error_format_test.rs b/crates/blockifier/src/transaction/error_format_test.rs
new file mode 100644
index 0000000000..fecae43c41
--- /dev/null
+++ b/crates/blockifier/src/transaction/error_format_test.rs
@@ -0,0 +1,16 @@
+use starknet_api::transaction::TransactionVersion;
+
+use crate::test_utils::CairoVersion;
+use crate::transaction::errors::TransactionExecutionError;
+
+#[test]
+fn test_contract_class_version_mismatch() {
+    let error = TransactionExecutionError::ContractClassVersionMismatch {
+        declare_version: TransactionVersion::ONE,
+        cairo_version: CairoVersion::Cairo0,
+    };
+    assert_eq!(
+        error.to_string(),
+        "Declare transaction version 1 must have a contract class of Cairo version Cairo0."
+    );
+}
diff --git a/crates/blockifier/src/transaction/errors.rs b/crates/blockifier/src/transaction/errors.rs
index fc7c141e9f..38e9de147b 100644
--- a/crates/blockifier/src/transaction/errors.rs
+++ b/crates/blockifier/src/transaction/errors.rs
@@ -10,6 +10,7 @@ use crate::execution::errors::{ConstructorEntryPointExecutionError, EntryPointEx
 use crate::execution::stack_trace::gen_transaction_execution_error_trace;
 use crate::fee::fee_checks::FeeCheckError;
 use crate::state::errors::StateError;
+use crate::test_utils::CairoVersion;
 
 // TODO(Yoni, 1/9/2024): implement Display for Fee.
 #[derive(Debug, Error)]
@@ -50,10 +51,13 @@ pub enum TransactionFeeError {
 #[derive(Debug, Error)]
 pub enum TransactionExecutionError {
     #[error(
-        "Declare transaction version {declare_version:?} must have a contract class of Cairo \
-         version {cairo_version:?}."
+        "Declare transaction version {} must have a contract class of Cairo \
+         version {cairo_version:?}.", **declare_version
     )]
-    ContractClassVersionMismatch { declare_version: TransactionVersion, cairo_version: u64 },
+    ContractClassVersionMismatch {
+        declare_version: TransactionVersion,
+        cairo_version: CairoVersion,
+    },
     #[error(
         "Contract constructor execution has failed:\n{}",
         String::from(gen_transaction_execution_error_trace(self))
diff --git a/crates/blockifier/src/transaction/transaction_utils.rs b/crates/blockifier/src/transaction/transaction_utils.rs
index 1f4edc40c4..c8722b89d9 100644
--- a/crates/blockifier/src/transaction/transaction_utils.rs
+++ b/crates/blockifier/src/transaction/transaction_utils.rs
@@ -2,6 +2,7 @@ use starknet_api::transaction::TransactionVersion;
 
 use crate::execution::call_info::CallInfo;
 use crate::execution::contract_class::ContractClass;
+use crate::test_utils::CairoVersion;
 use crate::transaction::errors::TransactionExecutionError;
 
 pub fn update_remaining_gas(remaining_gas: &mut u64, call_info: &CallInfo) {
@@ -22,7 +23,7 @@ pub fn verify_contract_class_version(
             }
             Err(TransactionExecutionError::ContractClassVersionMismatch {
                 declare_version,
-                cairo_version: 0,
+                cairo_version: CairoVersion::Cairo0,
             })
         }
         ContractClass::V1(_) => {
@@ -33,7 +34,7 @@ pub fn verify_contract_class_version(
             }
             Err(TransactionExecutionError::ContractClassVersionMismatch {
                 declare_version,
-                cairo_version: 1,
+                cairo_version: CairoVersion::Cairo1,
             })
         }
     }