diff --git a/proto/utxorpc/v1beta/cardano/cardano.proto b/proto/utxorpc/v1beta/cardano/cardano.proto
index 24e54fa..aac84fe 100644
--- a/proto/utxorpc/v1beta/cardano/cardano.proto
+++ b/proto/utxorpc/v1beta/cardano/cardano.proto
@@ -544,15 +544,15 @@ message UpdateDRepCert {
 
 // Pattern of an address that can be used to evaluate matching predicates.
 message AddressPattern {
-  bytes exact_address = 1; // The address should match this exact address value.
-  bytes payment_part = 2; // The payment part of the address should match this value.
-  bytes delegation_part = 3; // The delegation part of the address should match this value.
+  optional bytes exact_address = 1; // The address should match this exact address value.
+  optional bytes payment_part = 2; // The payment part of the address should match this value.
+  optional bytes delegation_part = 3; // The delegation part of the address should match this value.
 }
 
 // Pattern of a native asset that can be used to evaluate matching predicates.
 message AssetPattern {
-  bytes policy_id = 1; // The asset should belong to this policy id
-  bytes asset_name = 2; // The asset should present this name
+  optional bytes policy_id = 1; // The asset should belong to this policy id
+  optional bytes asset_name = 2; // The asset should present this name
 }
 
 // Pattern of a certificate that can be used to evaluate matching predicates.
@@ -589,8 +589,8 @@ message PoolRetirementPattern {
 
 // Pattern of a tx output that can be used to evaluate matching predicates.
 message TxOutputPattern {
-  AddressPattern address = 1; // Match any address in the output that exhibits this pattern.
-  AssetPattern asset = 2; // Match any asset in the output that exhibits this pattern.
+  optional AddressPattern address = 1; // Match any address in the output that exhibits this pattern.
+  optional AssetPattern asset = 2; // Match any asset in the output that exhibits this pattern.
 }
 
 // Pattern of a Tx that can be used to evaluate matching predicates.
diff --git a/proto/utxorpc/v1beta/query/query.proto b/proto/utxorpc/v1beta/query/query.proto
index 8e83fa0..ba6c333 100644
--- a/proto/utxorpc/v1beta/query/query.proto
+++ b/proto/utxorpc/v1beta/query/query.proto
@@ -81,7 +81,7 @@ message AnyUtxoPattern {
 
 // Represents a simple utxo predicate that can composed to create more complex ones
 message UtxoPredicate {
-  AnyUtxoPattern match = 1; // Predicate is true if tx exhibits pattern.
+  optional AnyUtxoPattern match = 1; // Predicate is true if tx exhibits pattern.
   repeated UtxoPredicate not = 2; // Predicate is true if tx doesn't exhibit pattern.
   repeated UtxoPredicate all_of = 3; // Predicate is true if utxo exhibits all of the patterns.
   repeated UtxoPredicate any_of = 4; // Predicate is true if utxo exhibits any of the patterns.
@@ -111,17 +111,17 @@ message ReadUtxosResponse {
 
 // Request to search for UTxO based on a pattern.
 message SearchUtxosRequest {
-  UtxoPredicate predicate = 1; // Pattern to match UTxOs by.
+  optional UtxoPredicate predicate = 1; // Pattern to match UTxOs by.
   google.protobuf.FieldMask field_mask = 2; // Field mask to selectively return fields.
-  int32 max_items = 3; // The maximum number of items to return.
-  string start_token = 4; // The next_page_token value returned from a previous request, if any.
+  optional int32 max_items = 3; // The maximum number of items to return.
+  optional string start_token = 4; // The next_page_token value returned from a previous request, if any.
 }
 
 // Response containing the UTxOs that match the requested addresses.
 message SearchUtxosResponse {
   repeated AnyUtxoData items = 1; // List of UTxOs.
   ChainPoint ledger_tip = 2; // The chain point that represent the ledger current position.
-  string next_token = 3; // Token to retrieve the next page of results, or empty if there are no more results.
+  optional string next_token = 3; // Token to retrieve the next page of results, absent if there are no more results.
 }
 
 // Request to get data (as in plural of datum)