diff --git a/listings/ch00-getting-started/custom_type_serde/src/contract.cairo b/listings/ch00-getting-started/custom_type_serde/src/contract.cairo
index 2b35f76d..e4981b29 100644
--- a/listings/ch00-getting-started/custom_type_serde/src/contract.cairo
+++ b/listings/ch00-getting-started/custom_type_serde/src/contract.cairo
@@ -1,3 +1,9 @@
+#[starknet::interface]
+trait ISerdeCustomType<TContractState> {
+    fn person_input(ref self: TContractState, person: SerdeCustomType::Person);
+    fn person_output(self: @TContractState) -> SerdeCustomType::Person;
+}
+
 #[starknet::contract]
 mod SerdeCustomType {
     #[storage]
@@ -11,13 +17,10 @@ mod SerdeCustomType {
         name: felt252
     }
 
-    #[abi(per_item)]
-    #[generate_trait]
-    impl SerdeCustomType of ISerdeCustomType {
-        #[external(v0)]
+    #[abi(embed_v0)]
+    impl SerdeCustomType of super::ISerdeCustomType<ContractState> {
         fn person_input(ref self: ContractState, person: Person) {}
 
-        #[external(v0)]
         fn person_output(self: @ContractState) -> Person {
             Person { age: 10, name: 'Joe' }
         }
diff --git a/listings/ch00-getting-started/custom_type_serde/src/tests.cairo b/listings/ch00-getting-started/custom_type_serde/src/tests.cairo
index 361dba07..0ef4b63d 100644
--- a/listings/ch00-getting-started/custom_type_serde/src/tests.cairo
+++ b/listings/ch00-getting-started/custom_type_serde/src/tests.cairo
@@ -1,2 +1,50 @@
-mod tests { // TODO
+// The purpose of these tests is to demonstrate the capability of using custom types as inputs and outputs in contract calls.
+// Therefore, we are not employing getters and setters for managing the contract's state.
+
+mod tests {
+    use custom_type_serde::contract::{
+        SerdeCustomType, SerdeCustomType::Person, ISerdeCustomTypeDispatcher,
+        ISerdeCustomTypeDispatcherTrait
+    };
+    use core::result::ResultTrait;
+    use debug::PrintTrait;
+    use starknet::{deploy_syscall, ContractAddress};
+    use starknet::class_hash::Felt252TryIntoClassHash;
+
+    fn deploy() -> ISerdeCustomTypeDispatcher {
+        let calldata: Array<felt252> = array![];
+        let (address0, _) = deploy_syscall(
+            SerdeCustomType::TEST_CLASS_HASH.try_into().unwrap(), 0, calldata.span(), false
+        )
+            .unwrap();
+        ISerdeCustomTypeDispatcher { contract_address: address0 }
+    }
+
+    #[test]
+    #[available_gas(2000000000)]
+    fn should_deploy() {
+        let init_value = 10;
+        let contract = deploy();
+    }
+
+    #[test]
+    #[available_gas(2000000000)]
+    fn should_get_person_output() {
+        let contract = deploy();
+        let expected_person = Person { age: 10, name: 'Joe' };
+        let received_person = contract.person_output();
+        let age_received = received_person.age;
+        let name_received = received_person.name;
+
+        assert(age_received == expected_person.age, 'Wrong age value');
+        assert(name_received == expected_person.name, 'Wrong name value');
+    }
+
+    #[test]
+    #[available_gas(2000000000)]
+    fn should_call_person_input() {
+        let contract = deploy();
+        let expected_person = Person { age: 10, name: 'Joe' };
+        let received_person = contract.person_input(expected_person);
+    }
 }