diff --git a/generated_types/protos/influxdata/iox/catalog/v1/catalog.proto b/generated_types/protos/influxdata/iox/catalog/v1/catalog.proto
index 34ccfa5d70..befe01daa2 100644
--- a/generated_types/protos/influxdata/iox/catalog/v1/catalog.proto
+++ b/generated_types/protos/influxdata/iox/catalog/v1/catalog.proto
@@ -79,12 +79,14 @@ message Transaction {
 
     // Definition of how this transaction relates to previous transaction and how it should be processed.
     enum Encoding {
+        ENCODING_UNSPECIFIED = 0;
+
         // The actions in this message only encode changes to the previous transactions which must be processed
         // beforehand. This is the default for "ordinary" transactions.
-        DELTA = 0;
+        ENCODING_DELTA = 1;
 
         // The actions in this message contain the full state of the catalog at this point in time. This is used for checkpoints.
-        FULL = 1;
+        ENCODING_FULL = 2;
     }
 
     // Definition on how this transaction is encoded.
diff --git a/parquet_file/src/catalog.rs b/parquet_file/src/catalog.rs
index e9d4f30bbb..958110b09d 100644
--- a/parquet_file/src/catalog.rs
+++ b/parquet_file/src/catalog.rs
@@ -178,7 +178,7 @@ pub enum Error {
     DateTimeParseError { source: TryFromIntError },
 
     #[snafu(display(
-        "Internal: Cannot parse encoding in serialized catalog: {} is not a valid variant",
+        "Internal: Cannot parse encoding in serialized catalog: {} is not a valid, specified variant",
         data
     ))]
     EncodingParseError { data: i32 },
@@ -785,7 +785,13 @@ fn parse_timestamp(
 
 /// Parse encoding from protobuf.
 fn parse_encoding(encoding: i32) -> Result<proto::transaction::Encoding> {
-    proto::transaction::Encoding::from_i32(encoding).context(EncodingParseError { data: encoding })
+    let parsed = proto::transaction::Encoding::from_i32(encoding)
+        .context(EncodingParseError { data: encoding })?;
+    if parsed == proto::transaction::Encoding::Unspecified {
+        Err(Error::EncodingParseError { data: encoding })
+    } else {
+        Ok(parsed)
+    }
 }
 
 /// Key to address transactions.
@@ -2151,7 +2157,7 @@ mod tests {
         .await;
         assert_eq!(
             res.unwrap_err().to_string(),
-            "Internal: Cannot parse encoding in serialized catalog: -1 is not a valid variant"
+            "Internal: Cannot parse encoding in serialized catalog: -1 is not a valid, specified variant"
         );
     }
 
@@ -2192,6 +2198,43 @@ mod tests {
         );
     }
 
+    #[tokio::test]
+    async fn test_missing_encoding_in_transaction_file() {
+        let object_store = make_object_store();
+        let server_id = make_server_id();
+        let db_name = "db1";
+        let trace = assert_single_catalog_inmem_works(&object_store, server_id, db_name).await;
+
+        // break transaction file
+        assert!(trace.tkeys.len() >= 2);
+        let tkey = &trace.tkeys[0];
+        let path = file_path(
+            &object_store,
+            server_id,
+            db_name,
+            tkey,
+            FileType::Transaction,
+        );
+        let mut proto = load_transaction_proto(&object_store, &path).await.unwrap();
+        proto.encoding = 0;
+        store_transaction_proto(&object_store, &path, &proto)
+            .await
+            .unwrap();
+
+        // loading catalog should fail now
+        let res = PreservedCatalog::<TestCatalogState>::load(
+            Arc::clone(&object_store),
+            server_id,
+            db_name.to_string(),
+            (),
+        )
+        .await;
+        assert_eq!(
+            res.unwrap_err().to_string(),
+            "Internal: Cannot parse encoding in serialized catalog: 0 is not a valid, specified variant"
+        );
+    }
+
     #[tokio::test]
     async fn test_wrong_encoding_in_checkpoint_file() {
         let object_store = make_object_store();