diff --git a/core/src/main/kotlin/net/corda/core/transactions/ContractUpgradeTransactions.kt b/core/src/main/kotlin/net/corda/core/transactions/ContractUpgradeTransactions.kt
index dec8e61a07..3975d0d258 100644
--- a/core/src/main/kotlin/net/corda/core/transactions/ContractUpgradeTransactions.kt
+++ b/core/src/main/kotlin/net/corda/core/transactions/ContractUpgradeTransactions.kt
@@ -305,8 +305,8 @@ private constructor(
                 ContractUpgradeLedgerTransaction(
                         inputs,
                         wtx.notary,
-                        legacyContractAttachment ?: throw AttachmentResolutionException(wtx.legacyContractAttachmentId),
-                        upgradedContractAttachment ?: throw AttachmentResolutionException(wtx.upgradedContractAttachmentId),
+                        legacyContractAttachment,
+                        upgradedContractAttachment,
                         wtx.id,
                         wtx.privacySalt,
                         sigs,