diff --git a/crates/gateway/src/gateway.rs b/crates/gateway/src/gateway.rs
index a9bc173f..cc3c5a93 100644
--- a/crates/gateway/src/gateway.rs
+++ b/crates/gateway/src/gateway.rs
@@ -15,7 +15,7 @@ use cairo_lang_starknet_classes::casm_contract_class::{
 use lazy_static::lazy_static;
 use starknet_api::core::CompiledClassHash;
 use starknet_api::rpc_transaction::{RPCDeclareTransaction, RPCTransaction};
-use starknet_api::transaction::TransactionHash;
+use starknet_api::transaction::{Builtin, TransactionHash};
 use starknet_mempool_infra::component_runner::{ComponentRunner, ComponentStartError};
 use starknet_mempool_types::communication::SharedMempoolClient;
 use starknet_mempool_types::mempool_types::{Account, MempoolInput};
@@ -29,7 +29,9 @@ use crate::rpc_state_reader::RpcStateReaderFactory;
 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, get_sender_address, is_subsequence};
+use crate::utils::{
+    external_tx_to_thin_tx, get_sender_address, is_subsequence, IntoOsOrderEnumIteratorExt,
+};
 
 #[cfg(test)]
 #[path = "gateway_test.rs"]
@@ -205,15 +207,29 @@ impl ComponentRunner for Gateway {
     }
 }
 
+// List of supported builtins.
+// This is an explicit function so that it is explicitly desiced which builtins are supported.
+// If new builtins are added, they should be added here.
+fn is_supported_builtin(builtin: &Builtin) -> bool {
+    match builtin {
+        Builtin::RangeCheck
+        | Builtin::Pedersen
+        | Builtin::Poseidon
+        | Builtin::EcOp
+        | Builtin::Ecdsa
+        | Builtin::Bitwise
+        | Builtin::SegmentArena => true,
+        Builtin::Keccak => false,
+    }
+}
+
 // TODO(Arni): Add to a config.
-// TODO(Arni): Use the Builtin enum from Starknet-api, and explicitly tag each builtin as supported
-// or unsupported so that the compiler would alert us on new builtins.
 lazy_static! {
     static ref SUPPORTED_BUILTINS: Vec<String> = {
-        // The OS expects this order for the builtins.
-        const SUPPORTED_BUILTIN_NAMES: [&str; 7] =
-            ["pedersen", "range_check", "ecdsa", "bitwise", "ec_op", "poseidon", "segment_arena"];
-        SUPPORTED_BUILTIN_NAMES.iter().map(|builtin| builtin.to_string()).collect::<Vec<String>>()
+        Builtin::os_order_iter()
+            .filter(is_supported_builtin)
+            .map(|builtin| builtin.name().to_string())
+            .collect::<Vec<String>>()
     };
 }
 
diff --git a/crates/gateway/src/utils.rs b/crates/gateway/src/utils.rs
index 6cebd08d..271859a9 100644
--- a/crates/gateway/src/utils.rs
+++ b/crates/gateway/src/utils.rs
@@ -10,8 +10,9 @@ use starknet_api::rpc_transaction::{
     RPCDeclareTransaction, RPCDeployAccountTransaction, RPCInvokeTransaction, RPCTransaction,
 };
 use starknet_api::transaction::{
-    DeclareTransaction, DeclareTransactionV3, DeployAccountTransaction, DeployAccountTransactionV3,
-    InvokeTransaction, InvokeTransactionV3, Tip, TransactionHash, TransactionHasher,
+    Builtin, DeclareTransaction, DeclareTransactionV3, DeployAccountTransaction,
+    DeployAccountTransactionV3, InvokeTransaction, InvokeTransactionV3, Tip, TransactionHash,
+    TransactionHasher,
 };
 use starknet_mempool_types::mempool_types::ThinTransaction;
 
@@ -176,3 +177,26 @@ pub fn is_subsequence<T: Eq>(subsequence: &[T], sequence: &[T]) -> bool {
 
     offset == subsequence.len()
 }
+
+// TODO(Arni): Remove the traitIntoEnumIteratorExt once EnumIter is implemented in starknet API.
+impl IntoOsOrderEnumIteratorExt for Builtin {
+    fn os_order_iter() -> impl Iterator<Item = Builtin> {
+        // The OS expects this order for the builtins.
+        vec![
+            Builtin::Pedersen,
+            Builtin::RangeCheck,
+            Builtin::Ecdsa,
+            Builtin::Bitwise,
+            Builtin::EcOp,
+            Builtin::Poseidon,
+            Builtin::SegmentArena,
+            Builtin::Keccak,
+        ]
+        .into_iter()
+    }
+}
+
+pub trait IntoOsOrderEnumIteratorExt {
+    /// Returns an iterator over all the builtins in the order the Starknet OS expects.
+    fn os_order_iter() -> impl Iterator<Item = Builtin>;
+}
diff --git a/crates/gateway/src/utils_test.rs b/crates/gateway/src/utils_test.rs
index 7b9d2fdb..6f2293e1 100644
--- a/crates/gateway/src/utils_test.rs
+++ b/crates/gateway/src/utils_test.rs
@@ -1,7 +1,8 @@
 use pretty_assertions::assert_eq;
 use rstest::rstest;
+use starknet_api::transaction::Builtin;
 
-use crate::utils::is_subsequence;
+use crate::utils::{is_subsequence, IntoOsOrderEnumIteratorExt};
 
 #[rstest]
 #[case::empty(
@@ -76,3 +77,20 @@ fn test_is_subsequence(
 ) {
     assert_eq!(is_subsequence(subsequence, sequence), expected_result);
 }
+
+#[test]
+fn test_os_order_iter() {
+    let expected_order = vec![
+        Builtin::Pedersen,
+        Builtin::RangeCheck,
+        Builtin::Ecdsa,
+        Builtin::Bitwise,
+        Builtin::EcOp,
+        Builtin::Poseidon,
+        Builtin::SegmentArena,
+        Builtin::Keccak,
+    ];
+
+    let actual_order = Builtin::os_order_iter().collect::<Vec<_>>();
+    assert_eq!(actual_order, expected_order);
+}