diff --git a/crates/native_blockifier/src/py_block_executor.rs b/crates/native_blockifier/src/py_block_executor.rs
index 7bf28040a1a..83d190c0bb7 100644
--- a/crates/native_blockifier/src/py_block_executor.rs
+++ b/crates/native_blockifier/src/py_block_executor.rs
@@ -305,7 +305,7 @@ impl PyBlockExecutor {
         previous_block_id: Option<PyFelt>,
         py_block_info: PyBlockInfo,
         py_state_diff: PyStateDiff,
-        declared_class_hash_to_class: HashMap<PyFelt, (PyFelt, String)>,
+        declared_class_hash_to_class: HashMap<PyFelt, (String, (PyFelt, String))>,
         deprecated_declared_class_hash_to_class: HashMap<PyFelt, String>,
     ) -> NativeBlockifierResult<()> {
         self.storage.append_block(
diff --git a/crates/native_blockifier/src/py_block_executor_test.rs b/crates/native_blockifier/src/py_block_executor_test.rs
index 0f5b59426dd..0b875c50098 100644
--- a/crates/native_blockifier/src/py_block_executor_test.rs
+++ b/crates/native_blockifier/src/py_block_executor_test.rs
@@ -7,6 +7,7 @@ use cached::Cached;
 use cairo_lang_starknet_classes::casm_contract_class::CasmContractClass;
 use pretty_assertions::assert_eq;
 use starknet_api::class_hash;
+use starknet_api::state::ContractClass;
 use starknet_types_core::felt::Felt;
 
 use crate::py_block_executor::{PyBlockExecutor, PyOsConfig};
@@ -19,6 +20,7 @@ use crate::test_utils::MockStorage;
 fn global_contract_cache_update() {
     // Initialize executor and set a contract class on the state.
     let casm = CasmContractClass { compiler_version: "0.1.0".to_string(), ..Default::default() };
+    let sierra = ContractClass::default();
     let contract_class =
         RunnableContractClass::V1(ContractClassV1::try_from(casm.clone()).unwrap());
     let class_hash = class_hash!("0x1");
@@ -38,7 +40,10 @@ fn global_contract_cache_update() {
             PyStateDiff::default(),
             HashMap::from([(
                 class_hash.into(),
-                (PyFelt::from(1_u8), serde_json::to_string(&casm).unwrap()),
+                (
+                    serde_json::to_string(&sierra).unwrap(),
+                    (PyFelt::from(1_u8), serde_json::to_string(&casm).unwrap()),
+                ),
             )]),
             HashMap::default(),
         )
diff --git a/crates/native_blockifier/src/storage.rs b/crates/native_blockifier/src/storage.rs
index 50b3a7efa5d..dfae73cb17f 100644
--- a/crates/native_blockifier/src/storage.rs
+++ b/crates/native_blockifier/src/storage.rs
@@ -116,7 +116,7 @@ impl Storage for PapyrusStorage {
         previous_block_id: Option<PyFelt>,
         py_block_info: PyBlockInfo,
         py_state_diff: PyStateDiff,
-        declared_class_hash_to_class: HashMap<PyFelt, (PyFelt, String)>,
+        declared_class_hash_to_class: HashMap<PyFelt, (String, (PyFelt, String))>,
         deprecated_declared_class_hash_to_class: HashMap<PyFelt, String>,
     ) -> NativeBlockifierResult<()> {
         log::debug!(
@@ -167,7 +167,9 @@ impl Storage for PapyrusStorage {
 
         let mut declared_classes = IndexMap::<ClassHash, (CompiledClassHash, ContractClass)>::new();
         let mut undeclared_casm_contracts = Vec::<(ClassHash, CasmContractClass)>::new();
-        for (class_hash, (compiled_class_hash, raw_class)) in declared_class_hash_to_class {
+        for (class_hash, (raw_sierra, (compiled_class_hash, raw_casm))) in
+            declared_class_hash_to_class
+        {
             let class_hash = ClassHash(class_hash.0);
             let class_undeclared = self
                 .reader()
@@ -177,12 +179,13 @@ impl Storage for PapyrusStorage {
                 .is_none();
 
             if class_undeclared {
+                let sierra_contract_class: ContractClass = serde_json::from_str(&raw_sierra)?;
                 declared_classes.insert(
                     class_hash,
-                    (CompiledClassHash(compiled_class_hash.0), ContractClass::default()),
+                    (CompiledClassHash(compiled_class_hash.0), sierra_contract_class),
                 );
-                let contract_class: CasmContractClass = serde_json::from_str(&raw_class)?;
-                undeclared_casm_contracts.push((class_hash, contract_class));
+                let casm_contract_class: CasmContractClass = serde_json::from_str(&raw_casm)?;
+                undeclared_casm_contracts.push((class_hash, casm_contract_class));
             }
         }
 
@@ -295,7 +298,7 @@ pub trait Storage {
         previous_block_id: Option<PyFelt>,
         py_block_info: PyBlockInfo,
         py_state_diff: PyStateDiff,
-        declared_class_hash_to_class: HashMap<PyFelt, (PyFelt, String)>,
+        declared_class_hash_to_class: HashMap<PyFelt, (String, (PyFelt, String))>,
         deprecated_declared_class_hash_to_class: HashMap<PyFelt, String>,
     ) -> NativeBlockifierResult<()>;
 
diff --git a/crates/native_blockifier/src/test_utils.rs b/crates/native_blockifier/src/test_utils.rs
index 13a2626ecc4..e2d8fa72211 100644
--- a/crates/native_blockifier/src/test_utils.rs
+++ b/crates/native_blockifier/src/test_utils.rs
@@ -33,7 +33,7 @@ impl Storage for MockStorage {
         _py_state_diff: crate::py_state_diff::PyStateDiff,
         _declared_class_hash_to_class: HashMap<
             crate::py_utils::PyFelt,
-            (crate::py_utils::PyFelt, String),
+            (String, (crate::py_utils::PyFelt, String)),
         >,
         _deprecated_declared_class_hash_to_class: HashMap<crate::py_utils::PyFelt, String>,
     ) -> NativeBlockifierResult<()> {