diff --git a/crates/gateway/src/errors.rs b/crates/gateway/src/errors.rs
index 3b65f783d..d3effbbc0 100644
--- a/crates/gateway/src/errors.rs
+++ b/crates/gateway/src/errors.rs
@@ -22,7 +22,7 @@ pub enum GatewayError {
     CompilationError(#[from] starknet_sierra_compile::compile::CompilationUtilError),
     #[error(
         "The supplied compiled class hash {supplied:?} does not match the hash of the Casm class \
-         compiled from the supplied Sierra {hash_result:?}."
+         compiled from the supplied Sierra {hash_result:?}"
     )]
     CompiledClassHashMismatch { supplied: CompiledClassHash, hash_result: CompiledClassHash },
     #[error(transparent)]
@@ -37,6 +37,8 @@ pub enum GatewayError {
     StatefulTransactionValidatorError(#[from] StatefulTransactionValidatorError),
     #[error(transparent)]
     StatelessTransactionValidatorError(#[from] StatelessTransactionValidatorError),
+    #[error("{builtins:?} is not a subsquence of {supported_builtins:?}")]
+    SupportedBuiltins { builtins: Vec<String>, supported_builtins: Vec<String> },
 }
 
 impl IntoResponse for GatewayError {
diff --git a/crates/gateway/src/gateway.rs b/crates/gateway/src/gateway.rs
index 12464589d..b8afb53cf 100644
--- a/crates/gateway/src/gateway.rs
+++ b/crates/gateway/src/gateway.rs
@@ -8,6 +8,9 @@ use axum::routing::{get, post};
 use axum::{Json, Router};
 use blockifier::execution::contract_class::{ClassInfo, ContractClass, ContractClassV1};
 use blockifier::execution::execution_utils::felt_to_stark_felt;
+use cairo_lang_starknet_classes::casm_contract_class::{
+    CasmContractClass, CasmContractEntryPoints,
+};
 use starknet_api::core::CompiledClassHash;
 use starknet_api::rpc_transaction::{RPCDeclareTransaction, RPCTransaction};
 use starknet_api::transaction::TransactionHash;
@@ -22,7 +25,7 @@ use crate::starknet_api_test_utils::get_sender_address;
 use crate::state_reader::StateReaderFactory;
 use crate::stateful_transaction_validator::StatefulTransactionValidator;
 use crate::stateless_transaction_validator::StatelessTransactionValidator;
-use crate::utils::external_tx_to_thin_tx;
+use crate::utils::{external_tx_to_thin_tx, is_subsequence};
 
 #[cfg(test)]
 #[path = "gateway_test.rs"]
@@ -158,6 +161,7 @@ pub fn compile_contract_class(declare_tx: &RPCDeclareTransaction) -> GatewayResu
             return Err(GatewayError::CompilationError(CompilationUtilError::CompilationPanic));
         }
     };
+    validate_casm_class(&casm_contract_class)?;
 
     let hash_result =
         CompiledClassHash(felt_to_stark_felt(&casm_contract_class.compiled_class_hash()));
@@ -178,3 +182,29 @@ pub fn compile_contract_class(declare_tx: &RPCDeclareTransaction) -> GatewayResu
     )?;
     Ok(class_info)
 }
+
+// TODO(Arni): Add to a config.
+fn get_supported_builtins() -> Vec<String> {
+    let builtins =
+        ["pedersen", "range_check", "ecdsa", "bitwise", "ec_op", "poseidon", "segment_arena"];
+    builtins.iter().map(|builtin| builtin.to_string()).collect()
+}
+
+// TODO(Arni): Add test.
+fn validate_casm_class(contract_class: &CasmContractClass) -> Result<(), GatewayError> {
+    let CasmContractEntryPoints { external, l1_handler, constructor } =
+        &contract_class.entry_points_by_type;
+    let entry_points_iterator = external.iter().chain(l1_handler.iter()).chain(constructor.iter());
+
+    let supported_builtins = &get_supported_builtins();
+    for entry_point in entry_points_iterator {
+        let builtins = &entry_point.builtins;
+        if !is_subsequence(builtins, supported_builtins) {
+            return Err(GatewayError::SupportedBuiltins {
+                builtins: builtins.clone(),
+                supported_builtins: supported_builtins.clone(),
+            });
+        }
+    }
+    Ok(())
+}
diff --git a/crates/gateway/src/utils.rs b/crates/gateway/src/utils.rs
index 2e438f63e..b371f57a4 100644
--- a/crates/gateway/src/utils.rs
+++ b/crates/gateway/src/utils.rs
@@ -18,6 +18,10 @@ use starknet_mempool_types::mempool_types::ThinTransaction;
 use crate::errors::StatefulTransactionValidatorResult;
 use crate::starknet_api_test_utils::get_sender_address;
 
+#[cfg(test)]
+#[path = "utils_test.rs"]
+mod utils_test;
+
 macro_rules! implement_ref_getters {
     ($(($member_name:ident, $member_type:ty));* $(;)?) => {
         $(fn $member_name(&self) -> &$member_type {
@@ -145,3 +149,14 @@ pub fn get_tx_hash(tx: &AccountTransaction) -> TransactionHash {
         AccountTransaction::Invoke(tx) => tx.tx_hash,
     }
 }
+
+/// Checks whether 'subsequence' is a subsequence of 'sequence'.
+pub fn is_subsequence(subsequence: &[String], sequence: &[String]) -> bool {
+    let mut seq_iter = sequence.iter();
+    for item in subsequence {
+        if !seq_iter.any(|x| x == item) {
+            return false;
+        }
+    }
+    true
+}
diff --git a/crates/gateway/src/utils_test.rs b/crates/gateway/src/utils_test.rs
new file mode 100644
index 000000000..780a3cde8
--- /dev/null
+++ b/crates/gateway/src/utils_test.rs
@@ -0,0 +1,66 @@
+use pretty_assertions::assert_eq;
+use rstest::rstest;
+
+use crate::utils::is_subsequence;
+
+#[rstest]
+#[case::empty(&[], &[], true)]
+#[case::empty_subsequence(&[], &["a".to_string(), "b".to_string()], true)]
+#[case::empty_sequence(&["a".to_string()], &[], false)]
+#[case::subsequence_1(
+    &["a".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    true
+)]
+#[case::subsequence_1(
+    &["b".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    true
+)]
+#[case::subsequence_1(
+    &["c".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    true
+)]
+#[case::subsequence_4(
+    &["a".to_string(), "b".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    true
+)]
+#[case::subsequence_5(
+    &["a".to_string(), "c".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    true
+)]
+#[case::subsequence_6(
+    &["b".to_string(), "c".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    true
+)]
+#[case::subsequence_7(
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    true
+)]
+#[case::out_of_order_1(
+    &["b".to_string(), "a".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    false
+)]
+#[case::out_of_order_2(
+    &["b".to_string(), "a".to_string(), "c".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    false
+)]
+#[case::unrelated(
+    &["a".to_string(), "b".to_string(), "d".to_string()],
+    &["a".to_string(), "b".to_string(), "c".to_string()],
+    false
+)]
+fn test_is_subsequence(
+    #[case] subsequence: &[String],
+    #[case] sequence: &[String],
+    #[case] expected_result: bool,
+) {
+    assert_eq!(is_subsequence(subsequence, sequence), expected_result);
+}