diff --git a/cardano-api/gen/Test/Gen/Cardano/Api/Typed.hs b/cardano-api/gen/Test/Gen/Cardano/Api/Typed.hs
index 0158bf859dd..788e9c5fc85 100644
--- a/cardano-api/gen/Test/Gen/Cardano/Api/Typed.hs
+++ b/cardano-api/gen/Test/Gen/Cardano/Api/Typed.hs
@@ -851,7 +851,7 @@ genProtocolParameters era = do
   protocolParamPoolPledgeInfluence <- genRationalInt64
   protocolParamMonetaryExpansion <- genRational
   protocolParamTreasuryCut <- genRational
-  protocolParamUTxOCostPerWord <- Gen.maybe genLovelace
+  protocolParamUTxOCostPerWord <- sequence $ protocolUTxOCostPerWordSupportedInEra era $> genLovelace
   protocolParamCostModels <- pure mempty
   --TODO: Babbage figure out how to deal with
   -- asymmetric cost model JSON instances
@@ -884,7 +884,7 @@ genProtocolParametersUpdate era = do
   protocolUpdatePoolPledgeInfluence <- Gen.maybe genRationalInt64
   protocolUpdateMonetaryExpansion   <- Gen.maybe genRational
   protocolUpdateTreasuryCut         <- Gen.maybe genRational
-  protocolUpdateUTxOCostPerWord     <- Gen.maybe genLovelace
+  protocolUpdateUTxOCostPerWord     <- sequence $ protocolUTxOCostPerWordSupportedInEra era $> genLovelace
   let protocolUpdateCostModels = mempty -- genCostModels
   --TODO: Babbage figure out how to deal with
   -- asymmetric cost model JSON instances