diff --git a/crates/cli/src/args.rs b/crates/cli/src/args.rs
index 3ed2cfe7..484624d8 100644
--- a/crates/cli/src/args.rs
+++ b/crates/cli/src/args.rs
@@ -50,7 +50,7 @@ pub enum TxCommand {
 
         /// Time between each slot
         #[clap(short, long, default_value_t = 1000)]
-        slot_length: u64,
+        slot_length: u32,
 
         /// Time of shelley hardfork
         #[clap(long, default_value_t = 1596059091000)]
diff --git a/crates/uplc/src/tx.rs b/crates/uplc/src/tx.rs
index 1030742d..cf0053e8 100644
--- a/crates/uplc/src/tx.rs
+++ b/crates/uplc/src/tx.rs
@@ -74,7 +74,7 @@ pub fn eval_phase_two_raw(
     utxos_bytes: &[(Vec<u8>, Vec<u8>)],
     cost_mdls_bytes: &[u8],
     initial_budget: (u64, u64),
-    slot_config: (u64, u64, u64),
+    slot_config: (u64, u64, u32),
     run_phase_one: bool,
 ) -> Result<Vec<Vec<u8>>, Error> {
     let multi_era_tx = MultiEraTx::decode(Era::Babbage, tx_bytes)
diff --git a/crates/uplc/src/tx/eval.rs b/crates/uplc/src/tx/eval.rs
index e58512ef..94d44dce 100644
--- a/crates/uplc/src/tx/eval.rs
+++ b/crates/uplc/src/tx/eval.rs
@@ -24,7 +24,7 @@ use super::{
 };
 
 fn slot_to_begin_posix_time(slot: u64, sc: &SlotConfig) -> u64 {
-    let ms_after_begin = (slot - sc.zero_slot) * sc.slot_length;
+    let ms_after_begin = (slot - sc.zero_slot) * sc.slot_length as u64;
     sc.zero_time + ms_after_begin
 }
 
diff --git a/crates/uplc/src/tx/script_context.rs b/crates/uplc/src/tx/script_context.rs
index 65497dec..50cb46e2 100644
--- a/crates/uplc/src/tx/script_context.rs
+++ b/crates/uplc/src/tx/script_context.rs
@@ -83,7 +83,7 @@ pub struct TimeRange {
 }
 
 pub struct SlotConfig {
-    pub slot_length: u64,
+    pub slot_length: u32,
     pub zero_slot: u64,
     pub zero_time: u64,
 }