diff --git a/integration_tests/src/data_changer.bin b/integration_tests/src/data_changer.bin
index 6a36d52c..3d062c30 100644
Binary files a/integration_tests/src/data_changer.bin and b/integration_tests/src/data_changer.bin differ
diff --git a/integration_tests/src/test_suite_map.rs b/integration_tests/src/test_suite_map.rs
index 17caf260..7ee3ef48 100644
--- a/integration_tests/src/test_suite_map.rs
+++ b/integration_tests/src/test_suite_map.rs
@@ -1466,7 +1466,7 @@ pub fn prepare_function_map() -> HashMap<String, TestFunction> {
             data_changer.id(),
             vec![account_id],
             vec![],
-            (),
+            vec![0],
         )
         .unwrap();
         let witness_set = nssa::public_transaction::WitnessSet::for_message(&message, &[]);
diff --git a/nssa/core/Cargo.toml b/nssa/core/Cargo.toml
index f179899a..80fe7df9 100644
--- a/nssa/core/Cargo.toml
+++ b/nssa/core/Cargo.toml
@@ -15,8 +15,8 @@ anyhow = { version = "1.0.98", optional = true }
 borsh = "1.5.7"
 
 [dev-dependencies]
-serde_json.workspace = true
+serde_json = "1.0.81"
 
 [features]
 default = []
-host = ["bytemuck", "k256", "base58", "anyhow"]
+host = ["dep:bytemuck", "dep:k256", "dep:base58", "dep:anyhow"]
diff --git a/nssa/core/src/account/data.rs b/nssa/core/src/account/data.rs
index 281599c2..974cb06c 100644
--- a/nssa/core/src/account/data.rs
+++ b/nssa/core/src/account/data.rs
@@ -3,9 +3,6 @@ use std::ops::Deref;
 use borsh::{BorshDeserialize, BorshSerialize};
 use serde::{Deserialize, Serialize};
 
-#[cfg(feature = "host")]
-use crate::error::NssaCoreError;
-
 pub const DATA_MAX_LENGTH_IN_BYTES: usize = 100 * 1024; // 100 KiB
 
 #[derive(Default, Clone, PartialEq, Eq, Serialize, BorshSerialize)]
@@ -18,7 +15,9 @@ impl Data {
     }
 
     #[cfg(feature = "host")]
-    pub fn from_cursor(cursor: &mut std::io::Cursor<&[u8]>) -> Result<Self, NssaCoreError> {
+    pub fn from_cursor(
+        cursor: &mut std::io::Cursor<&[u8]>,
+    ) -> Result<Self, crate::error::NssaCoreError> {
         use std::io::Read as _;
 
         let mut u32_bytes = [0u8; 4];
@@ -36,7 +35,7 @@ impl Data {
     }
 }
 
-#[derive(Debug, thiserror::Error)]
+#[derive(Debug, thiserror::Error, Clone, Copy, PartialEq, Eq)]
 #[error("data length exceeds maximum allowed length of {DATA_MAX_LENGTH_IN_BYTES} bytes")]
 pub struct DataTooBigError;
 
diff --git a/nssa/src/state.rs b/nssa/src/state.rs
index 5841f781..72efbd24 100644
--- a/nssa/src/state.rs
+++ b/nssa/src/state.rs
@@ -234,7 +234,7 @@ impl V02State {
                 program_owner: Program::pinata().id(),
                 balance: 1500,
                 // Difficulty: 3
-                data: vec![3; 33].try_into().unwrap(),
+                data: vec![3; 33].try_into().expect("should fit"),
                 nonce: 0,
             },
         );
@@ -730,7 +730,8 @@ pub mod tests {
             program_id
         );
         let message =
-            public_transaction::Message::try_new(program_id, vec![account_id], vec![], ()).unwrap();
+            public_transaction::Message::try_new(program_id, vec![account_id], vec![], vec![0])
+                .unwrap();
         let witness_set = public_transaction::WitnessSet::for_message(&message, &[]);
         let tx = PublicTransaction::new(message, witness_set);
 
@@ -1248,7 +1249,7 @@ pub mod tests {
 
         let result = execute_and_prove(
             &[public_account],
-            &Program::serialize_instruction(()).unwrap(),
+            &Program::serialize_instruction(vec![0]).unwrap(),
             &[0],
             &[],
             &[],
@@ -1259,6 +1260,34 @@ pub mod tests {
         assert!(matches!(result, Err(NssaError::CircuitProvingError(_))));
     }
 
+    #[test]
+    fn test_data_changer_program_should_fail_for_too_large_data_in_privacy_preserving_circuit() {
+        let program = Program::data_changer();
+        let public_account = AccountWithMetadata::new(
+            Account {
+                program_owner: program.id(),
+                balance: 0,
+                ..Account::default()
+            },
+            true,
+            AccountId::new([0; 32]),
+        );
+
+        let large_data: Vec<u8> = vec![0; nssa_core::account::data::DATA_MAX_LENGTH_IN_BYTES + 1];
+
+        let result = execute_and_prove(
+            &[public_account],
+            &Program::serialize_instruction(large_data).unwrap(),
+            &[0],
+            &[],
+            &[],
+            &[],
+            &program,
+        );
+
+        assert!(matches!(result, Err(NssaError::ProgramProveFailed(_))));
+    }
+
     #[test]
     fn test_extra_output_program_should_fail_in_privacy_preserving_circuit() {
         let program = Program::extra_output_program();
diff --git a/nssa/test_program_methods/guest/src/bin/data_changer.rs b/nssa/test_program_methods/guest/src/bin/data_changer.rs
index 16c23599..b5908864 100644
--- a/nssa/test_program_methods/guest/src/bin/data_changer.rs
+++ b/nssa/test_program_methods/guest/src/bin/data_changer.rs
@@ -1,9 +1,10 @@
 use nssa_core::program::{AccountPostState, ProgramInput, read_nssa_inputs, write_nssa_outputs};
 
-type Instruction = ();
+type Instruction = Vec<u8>;
 
+/// A program that modifies the account data by setting bytes sent in instruction.
 fn main() {
-    let ProgramInput { pre_states, .. } = read_nssa_inputs::<Instruction>();
+    let ProgramInput { pre_states, instruction: data } = read_nssa_inputs::<Instruction>();
 
     let [pre] = match pre_states.try_into() {
         Ok(array) => array,
@@ -12,9 +13,7 @@ fn main() {
 
     let account_pre = &pre.account;
     let mut account_post = account_pre.clone();
-    let mut data_vec = account_post.data.into_inner();
-    data_vec.push(0);
-    account_post.data = data_vec.try_into().expect("data_vec should fit into Data");
+    account_post.data = data.try_into().expect("provided data should fit into data limit");
 
     write_nssa_outputs(vec![pre], vec![AccountPostState::new_claimed(account_post)]);
 }