diff --git a/cardano-api/CHANGELOG.md b/cardano-api/CHANGELOG.md
index 04e9407ae4..c092681f3f 100644
--- a/cardano-api/CHANGELOG.md
+++ b/cardano-api/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog for cardano-api
 
+## 9.4.0.0 - UNRELEASED
+
+- **BREAKING** Text envelope type of `Tx era` is now always using the new `Witnessed Tx` prefix.
+
 ## 9.3.0.0
 - Upgrade `cardano-ledger-*`, `ouroboros-consensus-cardano`, `ouroboros-network-api`, `plutus-core` and `plutus-ledger-api`.
   (feature, breaking)
diff --git a/cardano-api/internal/Cardano/Api/Tx/Sign.hs b/cardano-api/internal/Cardano/Api/Tx/Sign.hs
index 00017e9fc7..483291c3dd 100644
--- a/cardano-api/internal/Cardano/Api/Tx/Sign.hs
+++ b/cardano-api/internal/Cardano/Api/Tx/Sign.hs
@@ -280,13 +280,14 @@ getTxBody (ShelleyTx sbe tx) =
 
 instance IsShelleyBasedEra era => HasTextEnvelope (Tx era) where
   textEnvelopeType _ =
-    case shelleyBasedEra :: ShelleyBasedEra era of
-      ShelleyBasedEraShelley -> "TxSignedShelley"
-      ShelleyBasedEraAllegra -> "Tx AllegraEra"
-      ShelleyBasedEraMary -> "Tx MaryEra"
-      ShelleyBasedEraAlonzo -> "Tx AlonzoEra"
-      ShelleyBasedEraBabbage -> "Tx BabbageEra"
-      ShelleyBasedEraConway -> "Tx ConwayEra"
+    "Witnessed Tx" <>
+      case shelleyBasedEra :: ShelleyBasedEra era of
+        ShelleyBasedEraShelley -> "ShelleyEra"
+        ShelleyBasedEraAllegra -> "AllegraEra"
+        ShelleyBasedEraMary -> "MaryEra"
+        ShelleyBasedEraAlonzo -> "AlonzoEra"
+        ShelleyBasedEraBabbage -> "BabbageEra"
+        ShelleyBasedEraConway -> "ConwayEra"
 
 -- ----------------------------------------------------------------------------
 -- Transaction bodies