diff --git a/pallas-alonzo/src/model.rs b/pallas-alonzo/src/model.rs
index 58821d2..40a2508 100644
--- a/pallas-alonzo/src/model.rs
+++ b/pallas-alonzo/src/model.rs
@@ -1152,7 +1152,7 @@ pub struct ExUnits {
     #[n(0)]
     pub mem: u32,
     #[n(1)]
-    pub steps: u32,
+    pub steps: u64,
 }
 
 #[derive(Encode, Decode, Debug, PartialEq)]