diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4ab23e59..1834b06f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 ### Changed
 
 - **aiken-project**: fix blueprint's apply truncating last character of outputs. See [#987](https://github.com/aiken-lang/aiken/issues/987). @KtorZ
+- **aiken-project**: provide better error (include input ref) when inputs are missing during transaction evaluation. See [#974](https://github.com/aiken-lang/aiken/issues/974). @KtorZ
 
 ### Removed
 
diff --git a/crates/uplc/src/tx/error.rs b/crates/uplc/src/tx/error.rs
index 02437e2e..5189bdba 100644
--- a/crates/uplc/src/tx/error.rs
+++ b/crates/uplc/src/tx/error.rs
@@ -1,4 +1,7 @@
-use crate::machine::{self, cost_model::ExBudget};
+use crate::{
+    machine::{self, cost_model::ExBudget},
+    TransactionInput,
+};
 
 #[derive(thiserror::Error, Debug, miette::Diagnostic)]
 pub enum Error {
@@ -24,7 +27,7 @@ pub enum Error {
     #[error("Extraneous redeemer")]
     ExtraneousRedeemer,
     #[error("Resolved Input not found.")]
-    ResolvedInputNotFound,
+    ResolvedInputNotFound(TransactionInput),
     #[error("A key hash cannot be the hash of a script.")]
     ScriptKeyHash,
     #[error("PlutusV1 cost model not found.")]
diff --git a/crates/uplc/src/tx/eval.rs b/crates/uplc/src/tx/eval.rs
index e19c4456..60306b55 100644
--- a/crates/uplc/src/tx/eval.rs
+++ b/crates/uplc/src/tx/eval.rs
@@ -1,22 +1,3 @@
-use crate::{
-    ast::{FakeNamedDeBruijn, NamedDeBruijn, Program},
-    machine::cost_model::ExBudget,
-    PlutusData,
-};
-use pallas_addresses::{Address, ScriptHash, StakePayload};
-use pallas_codec::utils::{KeyValuePairs, MaybeIndefArray};
-use pallas_crypto::hash::Hash;
-use pallas_primitives::babbage::{
-    Certificate, CostMdls, DatumHash, DatumOption, ExUnits, Mint, MintedTx, NativeScript,
-    PlutusV1Script, PlutusV2Script, PolicyId, PseudoScript, Redeemer, RedeemerTag, RewardAccount,
-    StakeCredential, TransactionInput, TransactionOutput, Value, Withdrawals,
-};
-use pallas_traverse::{ComputeHash, OriginalHash};
-
-use pallas_primitives::conway::Language;
-
-use std::{cmp::Ordering, collections::HashMap, convert::TryInto, ops::Deref, vec};
-
 use super::{
     script_context::{
         ResolvedInput, ScriptContext, ScriptPurpose, SlotConfig, TimeRange, TxInInfo, TxInfo,
@@ -25,7 +6,25 @@ use super::{
     to_plutus_data::{MintValue, ToPlutusData},
     Error,
 };
+use crate::{
+    ast::{FakeNamedDeBruijn, NamedDeBruijn, Program},
+    machine::cost_model::ExBudget,
+    PlutusData,
+};
 use itertools::Itertools;
+use pallas_addresses::{Address, ScriptHash, StakePayload};
+use pallas_codec::utils::{KeyValuePairs, MaybeIndefArray};
+use pallas_crypto::hash::Hash;
+use pallas_primitives::{
+    babbage::{
+        Certificate, CostMdls, DatumHash, DatumOption, ExUnits, Mint, MintedTx, NativeScript,
+        PlutusV1Script, PlutusV2Script, PolicyId, PseudoScript, Redeemer, RedeemerTag,
+        RewardAccount, StakeCredential, TransactionInput, TransactionOutput, Value, Withdrawals,
+    },
+    conway::Language,
+};
+use pallas_traverse::{ComputeHash, OriginalHash};
+use std::{cmp::Ordering, collections::HashMap, convert::TryInto, ops::Deref, vec};
 
 pub fn slot_to_begin_posix_time(slot: u64, sc: &SlotConfig) -> u64 {
     let ms_after_begin = (slot - sc.zero_slot) * sc.slot_length as u64;
@@ -134,7 +133,7 @@ pub fn get_tx_in_info_v1(
         .map(|input| {
             let utxo = match utxos.iter().find(|utxo| utxo.input == *input) {
                 Some(resolved) => resolved,
-                None => return Err(Error::ResolvedInputNotFound),
+                None => return Err(Error::ResolvedInputNotFound(input.clone())),
             };
             let address = Address::from_bytes(match &utxo.output {
                 TransactionOutput::Legacy(output) => output.address.as_ref(),
@@ -183,7 +182,7 @@ fn get_tx_in_info_v2(
         .map(|input| {
             let utxo = match utxos.iter().find(|utxo| utxo.input == *input) {
                 Some(resolved) => resolved,
-                None => return Err(Error::ResolvedInputNotFound),
+                None => return Err(Error::ResolvedInputNotFound(input.clone())),
             };
             let address = Address::from_bytes(match &utxo.output {
                 TransactionOutput::Legacy(output) => output.address.as_ref(),
@@ -494,7 +493,7 @@ fn get_execution_purpose(
                 None => {
                     return Err(Error::MissingRequiredScript {
                         hash: hash.to_string(),
-                    })
+                    });
                 }
             };
             Ok(ExecutionPurpose::NoDatum(script))
@@ -502,7 +501,7 @@ fn get_execution_purpose(
         ScriptPurpose::Spending(out_ref) => {
             let utxo = match utxos.iter().find(|utxo| utxo.input == *out_ref) {
                 Some(resolved) => resolved,
-                None => return Err(Error::ResolvedInputNotFound),
+                None => return Err(Error::ResolvedInputNotFound(out_ref.clone())),
             };
             match &utxo.output {
                 TransactionOutput::Legacy(output) => {
@@ -515,7 +514,7 @@ fn get_execution_purpose(
                                 None => {
                                     return Err(Error::MissingRequiredScript {
                                         hash: hash.to_string(),
-                                    })
+                                    });
                                 }
                             };
 
@@ -529,7 +528,7 @@ fn get_execution_purpose(
                                 None => {
                                     return Err(Error::MissingRequiredDatum {
                                         hash: datum_hash.to_string(),
-                                    })
+                                    });
                                 }
                             };
 
@@ -548,7 +547,7 @@ fn get_execution_purpose(
                                 None => {
                                     return Err(Error::MissingRequiredScript {
                                         hash: hash.to_string(),
-                                    })
+                                    });
                                 }
                             };
 
@@ -559,7 +558,7 @@ fn get_execution_purpose(
                                         None => {
                                             return Err(Error::MissingRequiredDatum {
                                                 hash: hash.to_string(),
-                                            })
+                                            });
                                         }
                                     }
                                 }
@@ -585,7 +584,7 @@ fn get_execution_purpose(
                 None => {
                     return Err(Error::MissingRequiredScript {
                         hash: script_hash.to_string(),
-                    })
+                    });
                 }
             };
 
@@ -603,7 +602,7 @@ fn get_execution_purpose(
                     None => {
                         return Err(Error::MissingRequiredScript {
                             hash: script_hash.to_string(),
-                        })
+                        });
                     }
                 };
 
@@ -620,7 +619,7 @@ fn get_execution_purpose(
                     None => {
                         return Err(Error::MissingRequiredScript {
                             hash: script_hash.to_string(),
-                        })
+                        });
                     }
                 };
 
diff --git a/crates/uplc/src/tx/phase_one.rs b/crates/uplc/src/tx/phase_one.rs
index 3fc3dc02..5adb5e04 100644
--- a/crates/uplc/src/tx/phase_one.rs
+++ b/crates/uplc/src/tx/phase_one.rs
@@ -1,16 +1,14 @@
-use std::collections::HashMap;
-
-use pallas_addresses::{Address, ScriptHash, ShelleyPaymentPart, StakePayload};
-use pallas_codec::utils::{KeyValuePairs, MaybeIndefArray};
-use pallas_primitives::babbage::{
-    Certificate, MintedTx, PolicyId, RedeemerTag, RewardAccount, StakeCredential, TransactionOutput,
-};
-
 use super::{
     error::Error,
     eval::{DataLookupTable, ScriptVersion},
     script_context::{ResolvedInput, ScriptPurpose},
 };
+use pallas_addresses::{Address, ScriptHash, ShelleyPaymentPart, StakePayload};
+use pallas_codec::utils::{KeyValuePairs, MaybeIndefArray};
+use pallas_primitives::babbage::{
+    Certificate, MintedTx, PolicyId, RedeemerTag, RewardAccount, StakeCredential, TransactionOutput,
+};
+use std::collections::HashMap;
 
 // TODO: include in pallas eventually?
 #[derive(Debug, PartialEq, Clone)]
@@ -83,7 +81,7 @@ pub fn scripts_needed(
     for input in txb.inputs.iter() {
         let utxo = match utxos.iter().find(|utxo| utxo.input == *input) {
             Some(u) => u,
-            None => return Err(Error::ResolvedInputNotFound),
+            None => return Err(Error::ResolvedInputNotFound(input.clone())),
         };
 
         let address = Address::from_bytes(match &utxo.output {