diff --git a/simconnect-sdk-derive/src/lib.rs b/simconnect-sdk-derive/src/lib.rs
index e41f886..1d57a2f 100644
--- a/simconnect-sdk-derive/src/lib.rs
+++ b/simconnect-sdk-derive/src/lib.rs
@@ -99,7 +99,7 @@ pub fn derive(input: TokenStream) -> TokenStream {
     let expanded = quote! {
         #[repr(C, packed)]
         #vis struct #packed_ident {
-            #(#packed_fields,)*
+            #(#vis #packed_fields,)*
         }
         impl simconnect_sdk::SimConnectObjectExt for #name_ident {
             fn register(client: &mut simconnect_sdk::SimConnect, id: u32) -> Result<(), simconnect_sdk::SimConnectError> {
@@ -193,6 +193,11 @@ fn build_sc_definition(
                 client.add_to_data_definition(id, #name, #unit, simconnect_sdk::DataType::String)?;
             }
         }
+        Some(value) if value == "[i8; 256]" => {
+            quote! {
+                client.add_to_data_definition(id, #name, #unit, simconnect_sdk::DataType::String)?;
+            }
+        }
         _ => {
             // this error is already caught in `parse_field_attributes`
             mk_err(path, error_message)
diff --git a/testapp/src/main.rs b/testapp/src/main.rs
index b1c884e..b0f51c0 100644
--- a/testapp/src/main.rs
+++ b/testapp/src/main.rs
@@ -1,4 +1,5 @@
 mod ctrl_c;
+mod models;
 
 use std::{
     borrow::Cow,
@@ -8,54 +9,9 @@ use std::{
 };
 
 use ctrl_c::CtrlC;
+use models::{AtcID, AtcIDCPacked, Fuel};
 // use simconnect_rs::SimConnect;
-use simconnect_sdk::{Notification, SimConnect, SimConnectObject, SystemEventRequest};
-
-#[derive(Debug, Clone, SimConnectObject)]
-#[simconnect(period = "second")]
-struct AtcID {
-    #[simconnect(name = "ATC ID")]
-    value: String,
-}
-
-// #[derive(Debug, Clone, SimConnectObject)]
-// #[simconnect(period = "second")]
-// #[allow(dead_code)]
-// struct AirplaneData {
-//     #[simconnect(name = "TITLE")]
-//     title: String,
-//     #[simconnect(name = "ATC ID")]
-//     atc_id: String,
-//     #[simconnect(name = "CATEGORY")]
-//     category: String,
-//     #[simconnect(name = "PLANE LATITUDE", unit = "degrees")]
-//     lat: f64,
-//     #[simconnect(name = "PLANE LONGITUDE", unit = "degrees")]
-//     lon: f64,
-//     #[simconnect(name = "PLANE ALTITUDE", unit = "feet")]
-//     alt: f64,
-//     #[simconnect(name = "SIM ON GROUND")]
-//     sim_on_ground: bool,
-// }
-
-#[derive(Debug, Clone, SimConnectObject)]
-#[simconnect(period = "second")]
-struct Fuel {
-    #[simconnect(name = "FUEL TANK CENTER QUANTITY", unit = "gallons")]
-    ft1: f64,
-    #[simconnect(name = "FUEL TANK LEFT MAIN QUANTITY", unit = "gallons")]
-    wt1: f64,
-    #[simconnect(name = "FUEL TANK RIGHT MAIN QUANTITY", unit = "gallons")]
-    wt2: f64,
-    #[simconnect(name = "FUEL TANK EXTERNAL1 QUANTITY", unit = "gallons")]
-    et1: f64,
-    #[simconnect(name = "FUEL TANK EXTERNAL2 QUANTITY", unit = "gallons")]
-    et2: f64,
-    #[simconnect(name = "FUEL TANK CENTER3 QUANTITY", unit = "gallons")]
-    et3: f64,
-    #[simconnect(name = "FUEL TANK CENTER2 QUANTITY", unit = "gallons")]
-    ft2: f64,
-}
+use simconnect_sdk::{Notification, SimConnect, SystemEventRequest};
 
 fn main() -> Result<(), anyhow::Error> {
     use tracing::Level;
@@ -85,23 +41,22 @@ fn main() -> Result<(), anyhow::Error> {
                 Notification::Open => {
                     simconnect.subscribe_to_system_event(SystemEventRequest::FlightLoaded)?;
 
-                    id = simconnect.register_object::<AtcID>()?;
+                    simconnect.register_object::<AtcID>()?;
                     simconnect.register_object::<Fuel>()?;
 
-                    let cs = CString::new("FAST")?;
+                    let cs = CString::new("ITWORKS")?;
                     let mut buffer = [0i8; 256];
                     for (i, b) in cs.to_bytes_with_nul().iter().enumerate() {
                         buffer[i] = *b as i8;
                     }
 
-                    simconnect
-                        .set_data_on_sim_object_with_id(id, &mut AtcIDCPacked { value: buffer })?;
+                    simconnect.set_data_on_sim_object(&mut AtcID { value: buffer })?;
                     tracing::info!("ATC_ID set");
 
                     simconnect.set_data_on_sim_object(&mut Fuel {
                         ft1: 0.0,
-                        wt1: 20.0,
-                        wt2: 20.0,
+                        wt1: 10.0,
+                        wt2: 0.0,
                         et1: 0.0,
                         et2: 0.0,
                         et3: 0.0,
@@ -117,7 +72,7 @@ fn main() -> Result<(), anyhow::Error> {
                 }
                 Notification::SystemEvent(system_event) => {
                     if let simconnect_sdk::SystemEvent::FlightLoaded { .. } = system_event {
-                        let cs = CString::new("RAWR")?;
+                        let cs = CString::new("ITWORKS")?;
                         let mut buffer = [0i8; 256];
                         for (i, b) in cs.to_bytes_with_nul().iter().enumerate() {
                             buffer[i] = *b as i8;
@@ -131,8 +86,8 @@ fn main() -> Result<(), anyhow::Error> {
 
                         simconnect.set_data_on_sim_object(&mut Fuel {
                             ft1: 0.0,
-                            wt1: 20.0,
-                            wt2: 20.0,
+                            wt1: 10.0,
+                            wt2: 0.0,
                             et1: 0.0,
                             et2: 0.0,
                             et3: 0.0,
diff --git a/testapp/src/models.rs b/testapp/src/models.rs
new file mode 100644
index 0000000..8132fe0
--- /dev/null
+++ b/testapp/src/models.rs
@@ -0,0 +1,47 @@
+use simconnect_sdk::SimConnectObject;
+
+#[derive(Debug, Clone, SimConnectObject)]
+#[simconnect(period = "second")]
+pub(super) struct AtcID {
+    #[simconnect(name = "ATC ID")]
+    pub value: String,
+}
+
+// #[derive(Debug, Clone, SimConnectObject)]
+// #[simconnect(period = "second")]
+// #[allow(dead_code)]
+// struct AirplaneData {
+//     #[simconnect(name = "TITLE")]
+//     title: String,
+//     #[simconnect(name = "ATC ID")]
+//     atc_id: String,
+//     #[simconnect(name = "CATEGORY")]
+//     category: String,
+//     #[simconnect(name = "PLANE LATITUDE", unit = "degrees")]
+//     lat: f64,
+//     #[simconnect(name = "PLANE LONGITUDE", unit = "degrees")]
+//     lon: f64,
+//     #[simconnect(name = "PLANE ALTITUDE", unit = "feet")]
+//     alt: f64,
+//     #[simconnect(name = "SIM ON GROUND")]
+//     sim_on_ground: bool,
+// }
+
+#[derive(Debug, Clone, SimConnectObject)]
+#[simconnect(period = "second")]
+pub(super) struct Fuel {
+    #[simconnect(name = "FUEL TANK CENTER QUANTITY", unit = "gallons")]
+    pub ft1: f64,
+    #[simconnect(name = "FUEL TANK LEFT MAIN QUANTITY", unit = "gallons")]
+    pub wt1: f64,
+    #[simconnect(name = "FUEL TANK RIGHT MAIN QUANTITY", unit = "gallons")]
+    pub wt2: f64,
+    #[simconnect(name = "FUEL TANK EXTERNAL1 QUANTITY", unit = "gallons")]
+    pub et1: f64,
+    #[simconnect(name = "FUEL TANK EXTERNAL2 QUANTITY", unit = "gallons")]
+    pub et2: f64,
+    #[simconnect(name = "FUEL TANK CENTER3 QUANTITY", unit = "gallons")]
+    pub et3: f64,
+    #[simconnect(name = "FUEL TANK CENTER2 QUANTITY", unit = "gallons")]
+    pub ft2: f64,
+}