diff --git a/pallas-applying/src/alonzo.rs b/pallas-applying/src/alonzo.rs
index 109d9346..ac9cda01 100644
--- a/pallas-applying/src/alonzo.rs
+++ b/pallas-applying/src/alonzo.rs
@@ -378,7 +378,7 @@ fn check_tx_ex_units(mtx: &MintedTx, prot_pps: &AlonzoProtParams) -> ValidationR
         match &tx_wits.redeemer {
             Some(redeemers_vec) => {
                 let mut steps: u64 = 0;
-                let mut mem: u32 = 0;
+                let mut mem: u64 = 0;
                 for Redeemer { ex_units, .. } in redeemers_vec {
                     mem += ex_units.mem;
                     steps += ex_units.steps;
diff --git a/pallas-applying/src/babbage.rs b/pallas-applying/src/babbage.rs
index ea4b11bb..7e8b0c98 100644
--- a/pallas-applying/src/babbage.rs
+++ b/pallas-applying/src/babbage.rs
@@ -421,7 +421,7 @@ fn check_tx_ex_units(mtx: &MintedTx, prot_pps: &BabbageProtParams) -> Validation
         match &tx_wits.redeemer {
             Some(redeemers_vec) => {
                 let mut steps: u64 = 0;
-                let mut mem: u32 = 0;
+                let mut mem: u64 = 0;
                 for Redeemer { ex_units, .. } in redeemers_vec {
                     mem += ex_units.mem;
                     steps += ex_units.steps;
diff --git a/pallas-configs/src/alonzo.rs b/pallas-configs/src/alonzo.rs
index 124181c3..3537e8a1 100644
--- a/pallas-configs/src/alonzo.rs
+++ b/pallas-configs/src/alonzo.rs
@@ -20,7 +20,7 @@ impl From<ExecutionPrices> for pallas_primitives::alonzo::ExUnitPrices {
 #[derive(Deserialize, Clone)]
 #[serde(rename_all = "camelCase")]
 pub struct ExUnits {
-    pub ex_units_mem: u32,
+    pub ex_units_mem: u64,
     pub ex_units_steps: u64,
 }
 
diff --git a/pallas-primitives/src/alonzo/model.rs b/pallas-primitives/src/alonzo/model.rs
index 7bbc2546..a4c92e22 100644
--- a/pallas-primitives/src/alonzo/model.rs
+++ b/pallas-primitives/src/alonzo/model.rs
@@ -1200,7 +1200,7 @@ where
 #[derive(Serialize, Deserialize, Encode, Decode, Debug, PartialEq, Eq, Clone, Copy)]
 pub struct ExUnits {
     #[n(0)]
-    pub mem: u32,
+    pub mem: u64,
     #[n(1)]
     pub steps: u64,
 }
diff --git a/pallas-primitives/src/conway/model.rs b/pallas-primitives/src/conway/model.rs
index d6ac480b..25d8a99d 100644
--- a/pallas-primitives/src/conway/model.rs
+++ b/pallas-primitives/src/conway/model.rs
@@ -578,11 +578,11 @@ pub struct ProtocolParamUpdate {
     #[n(21)]
     pub max_block_ex_units: Option<ExUnits>,
     #[n(22)]
-    pub max_value_size: Option<u32>,
+    pub max_value_size: Option<u64>,
     #[n(23)]
-    pub collateral_percentage: Option<u32>,
+    pub collateral_percentage: Option<u64>,
     #[n(24)]
-    pub max_collateral_inputs: Option<u32>,
+    pub max_collateral_inputs: Option<u64>,
 
     #[n(25)]
     pub pool_voting_thresholds: Option<PoolVotingThresholds>,
@@ -601,7 +601,7 @@ pub struct ProtocolParamUpdate {
     #[n(32)]
     pub drep_inactivity_period: Option<Epoch>,
     #[n(33)]
-    pub minfee_refscript_cost_per_byte: Option<Epoch>,
+    pub minfee_refscript_cost_per_byte: Option<UnitInterval>,
 }
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
@@ -1712,6 +1712,8 @@ mod tests {
             include_str!("../../../test_data/conway2.block"),
             // interesting block with extreme values
             include_str!("../../../test_data/conway3.block"),
+            // interesting block with extreme values
+            include_str!("../../../test_data/conway4.block"),
         ];
 
         for (idx, block_str) in test_blocks.iter().enumerate() {
diff --git a/pallas-txbuilder/src/transaction/model.rs b/pallas-txbuilder/src/transaction/model.rs
index 9c94009e..87d13af4 100644
--- a/pallas-txbuilder/src/transaction/model.rs
+++ b/pallas-txbuilder/src/transaction/model.rs
@@ -554,7 +554,7 @@ pub enum RedeemerPurpose {
 
 #[derive(Serialize, Deserialize, PartialEq, Eq, Debug)]
 pub struct ExUnits {
-    pub mem: u32,
+    pub mem: u64,
     pub steps: u64,
 }
 
diff --git a/test_data/conway4.block b/test_data/conway4.block
new file mode 100644
index 00000000..db91113a
--- /dev/null
+++ b/test_data/conway4.block
@@ -0,0 +1 @@
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
\ No newline at end of file