diff --git a/pop-api/examples/fungibles/tests.rs b/pop-api/examples/fungibles/tests.rs
index 33ee18bd..57e93005 100644
--- a/pop-api/examples/fungibles/tests.rs
+++ b/pop-api/examples/fungibles/tests.rs
@@ -268,15 +268,19 @@ fn transfer_fails_with_insufficient_balance(
 	const AMOUNT: Balance = TOKEN_MIN_BALANCE * 4;
 	assert_ok!(session.sandbox().mint_into(&TOKEN_ID, &contract.clone(), AMOUNT));
 	assert_ok!(session.sandbox().mint_into(&TOKEN_ID, &BOB, AMOUNT));
+	assert_eq!(session.sandbox().balance_of(&TOKEN_ID, &contract.clone()), AMOUNT);
 
 	session.set_actor(contract.clone());
 	// Failed with `InsufficientBalance`.
+	let data = serde_json::to_string::<[u8; 0]>(&[]).unwrap();
 	expect_call_reverted(
 		&mut session,
 		TRANSFER,
-		vec![BOB.to_string(), (AMOUNT + 1).to_string()],
+		vec![BOB.to_string(), (AMOUNT + 1).to_string(), data],
 		PSP22Error::InsufficientBalance,
 	);
+	// Check that balance of account is not changed.
+	assert_eq!(session.sandbox().balance_of(&TOKEN_ID, &contract), AMOUNT);
 	Ok(())
 }
 
diff --git a/pop-api/examples/fungibles/utils.rs b/pop-api/examples/fungibles/utils.rs
index 44755f8b..fb6a1e3f 100644
--- a/pop-api/examples/fungibles/utils.rs
+++ b/pop-api/examples/fungibles/utils.rs
@@ -39,7 +39,7 @@ pub(super) fn last_contract_event(session: &Session<Sandbox>) -> Option<Vec<u8>>
 	session.record().last_event_batch().contract_events().last().cloned()
 }
 
-/// Execute a contract method and exepct CallReverted error to be returned.
+/// Execute a contract method and expect CallReverted error to be returned.
 pub(super) fn expect_call_reverted(
 	session: &mut Session<Sandbox>,
 	function: &str,
@@ -47,8 +47,11 @@ pub(super) fn expect_call_reverted(
 	err: PSP22Error,
 ) {
 	let call = session.call::<String, ()>(function, &params, None);
-	if let Err(SessionError::CallReverted(error)) = call {
-		assert_eq!(error[1..], Err::<(), PSP22Error>(err).encode());
+	match call {
+		Err(SessionError::CallReverted(error)) => {
+			assert_eq!(error[1..], Err::<(), PSP22Error>(err).encode())
+		},
+		_ => panic!("Expect call reverted"),
 	}
 }