diff --git a/src/bank.rs b/src/bank.rs
index 8b366cf7b6..2d1ec5cf47 100644
--- a/src/bank.rs
+++ b/src/bank.rs
@@ -536,12 +536,15 @@ impl Bank {
         // Call the contract method
         // It's up to the contract to implement its own rules on moving funds
         if SystemProgram::check_id(&tx_program_id) {
-            SystemProgram::process_transaction(
+            if SystemProgram::process_transaction(
                 &tx,
                 instruction_index,
                 program_accounts,
                 &self.loaded_contracts,
-            )
+            ).is_err()
+            {
+                return Err(BankError::ProgramRuntimeError(instruction_index as u8));
+            }
         } else if BudgetState::check_id(&tx_program_id) {
             if BudgetState::process_transaction(&tx, instruction_index, program_accounts).is_err() {
                 return Err(BankError::ProgramRuntimeError(instruction_index as u8));
diff --git a/src/system_program.rs b/src/system_program.rs
index f7176d741e..5d94959c80 100644
--- a/src/system_program.rs
+++ b/src/system_program.rs
@@ -4,10 +4,24 @@ use bincode::deserialize;
 use dynamic_program::DynamicProgram;
 use solana_program_interface::account::Account;
 use solana_program_interface::pubkey::Pubkey;
+use std;
 use std::collections::HashMap;
 use std::sync::RwLock;
 use transaction::Transaction;
 
+#[derive(Debug)]
+pub enum Error {
+    InvalidArgument,
+}
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "error")
+    }
+}
+impl std::error::Error for Error {}
+
+pub type Result<T> = std::result::Result<T, Error>;
+
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub enum SystemProgram {
     /// Create a new account
@@ -52,7 +66,7 @@ impl SystemProgram {
         pix: usize,
         accounts: &mut [&mut Account],
         loaded_programs: &RwLock<HashMap<Pubkey, DynamicProgram>>,
-    ) {
+    ) -> Result<()> {
         if let Ok(syscall) = deserialize(tx.userdata(pix)) {
             trace!("process_transaction: {:?}", syscall);
             match syscall {
@@ -62,13 +76,13 @@ impl SystemProgram {
                     program_id,
                 } => {
                     if !Self::check_id(&accounts[0].program_id) {
-                        return;
+                        Err(Error::InvalidArgument)?;
                     }
                     if space > 0
                         && (!accounts[1].userdata.is_empty()
                             || !Self::check_id(&accounts[1].program_id))
                     {
-                        return;
+                        Err(Error::InvalidArgument)?;
                     }
                     accounts[0].tokens -= tokens;
                     accounts[1].tokens += tokens;
@@ -77,7 +91,7 @@ impl SystemProgram {
                 }
                 SystemProgram::Assign { program_id } => {
                     if !Self::check_id(&accounts[0].program_id) {
-                        return;
+                        Err(Error::InvalidArgument)?;
                     }
                     accounts[0].program_id = program_id;
                 }
@@ -91,8 +105,10 @@ impl SystemProgram {
                     hashmap.insert(program_id, DynamicProgram::new_native(name));
                 }
             }
+            Ok(())
         } else {
             info!("Invalid transaction userdata: {:?}", tx.userdata(pix));
+            Err(Error::InvalidArgument)
         }
     }
 }
@@ -113,10 +129,11 @@ mod test {
         tx: &Transaction,
         accounts: &mut [Account],
         loaded_programs: &RwLock<HashMap<Pubkey, DynamicProgram>>,
-    ) {
+    ) -> Result<()> {
         let mut refs: Vec<&mut Account> = accounts.iter_mut().collect();
         SystemProgram::process_transaction(&tx, 0, &mut refs[..], loaded_programs)
     }
+
     #[test]
     fn test_create_noop() {
         let from = Keypair::new();
@@ -124,7 +141,7 @@ mod test {
         let mut accounts = vec![Account::default(), Account::default()];
         let tx = Transaction::system_new(&from, to.pubkey(), 0, Hash::default());
         let hash = RwLock::new(HashMap::new());
-        process_transaction(&tx, &mut accounts, &hash);
+        process_transaction(&tx, &mut accounts, &hash).unwrap();
         assert_eq!(accounts[0].tokens, 0);
         assert_eq!(accounts[1].tokens, 0);
     }
@@ -136,7 +153,7 @@ mod test {
         accounts[0].tokens = 1;
         let tx = Transaction::system_new(&from, to.pubkey(), 1, Hash::default());
         let hash = RwLock::new(HashMap::new());
-        process_transaction(&tx, &mut accounts, &hash);
+        process_transaction(&tx, &mut accounts, &hash).unwrap();
         assert_eq!(accounts[0].tokens, 0);
         assert_eq!(accounts[1].tokens, 1);
     }
@@ -149,7 +166,7 @@ mod test {
         accounts[0].program_id = from.pubkey();
         let tx = Transaction::system_new(&from, to.pubkey(), 1, Hash::default());
         let hash = RwLock::new(HashMap::new());
-        process_transaction(&tx, &mut accounts, &hash);
+        assert!(process_transaction(&tx, &mut accounts, &hash).is_err());
         assert_eq!(accounts[0].tokens, 1);
         assert_eq!(accounts[1].tokens, 0);
     }
@@ -161,7 +178,7 @@ mod test {
         let tx =
             Transaction::system_create(&from, to.pubkey(), Hash::default(), 0, 1, to.pubkey(), 0);
         let hash = RwLock::new(HashMap::new());
-        process_transaction(&tx, &mut accounts, &hash);
+        process_transaction(&tx, &mut accounts, &hash).unwrap();
         assert!(accounts[0].userdata.is_empty());
         assert_eq!(accounts[1].userdata.len(), 1);
         assert_eq!(accounts[1].program_id, to.pubkey());
@@ -182,7 +199,7 @@ mod test {
             0,
         );
         let hash = RwLock::new(HashMap::new());
-        process_transaction(&tx, &mut accounts, &hash);
+        assert!(process_transaction(&tx, &mut accounts, &hash).is_err());
         assert!(accounts[1].userdata.is_empty());
     }
     #[test]
@@ -201,7 +218,7 @@ mod test {
             0,
         );
         let hash = RwLock::new(HashMap::new());
-        process_transaction(&tx, &mut accounts, &hash);
+        assert!(process_transaction(&tx, &mut accounts, &hash).is_err());
         assert!(accounts[1].userdata.is_empty());
     }
     #[test]
@@ -220,7 +237,7 @@ mod test {
             0,
         );
         let hash = RwLock::new(HashMap::new());
-        process_transaction(&tx, &mut accounts, &hash);
+        assert!(process_transaction(&tx, &mut accounts, &hash).is_err());
         assert_eq!(accounts[1].userdata.len(), 3);
     }
     #[test]
@@ -230,7 +247,7 @@ mod test {
         let mut accounts = vec![Account::default()];
         let tx = Transaction::system_assign(&from, Hash::default(), program.pubkey(), 0);
         let hash = RwLock::new(HashMap::new());
-        process_transaction(&tx, &mut accounts, &hash);
+        process_transaction(&tx, &mut accounts, &hash).unwrap();
         assert_eq!(accounts[0].program_id, program.pubkey());
     }
     #[test]
@@ -241,7 +258,7 @@ mod test {
         accounts[0].tokens = 1;
         let tx = Transaction::system_new(&from, to.pubkey(), 1, Hash::default());
         let hash = RwLock::new(HashMap::new());
-        process_transaction(&tx, &mut accounts, &hash);
+        process_transaction(&tx, &mut accounts, &hash).unwrap();
         assert_eq!(accounts[0].tokens, 0);
         assert_eq!(accounts[1].tokens, 1);
     }
diff --git a/tests/programs.rs b/tests/programs.rs
index e5e62bbc46..54efa63463 100644
--- a/tests/programs.rs
+++ b/tests/programs.rs
@@ -236,7 +236,7 @@ fn process_transaction(
     loaded_programs: &RwLock<HashMap<Pubkey, DynamicProgram>>,
 ) {
     let mut refs: Vec<&mut Account> = accounts.iter_mut().collect();
-    SystemProgram::process_transaction(&tx, 0, &mut refs[..], loaded_programs)
+    SystemProgram::process_transaction(&tx, 0, &mut refs[..], loaded_programs).unwrap();
 }
 
 #[test]