diff --git a/packages/google-cloud-deploy/protos/google/cloud/deploy/v1/cloud_deploy.proto b/packages/google-cloud-deploy/protos/google/cloud/deploy/v1/cloud_deploy.proto
index 4e1d200c6f4..31f19e2b850 100644
--- a/packages/google-cloud-deploy/protos/google/cloud/deploy/v1/cloud_deploy.proto
+++ b/packages/google-cloud-deploy/protos/google/cloud/deploy/v1/cloud_deploy.proto
@@ -2468,12 +2468,12 @@ message Release {
   // client has an up-to-date value before proceeding.
   string etag = 16;
 
-  // The Skaffold version to use when operating on this release, such as
-  // "1.20.0". Not all versions are valid; Cloud Deploy supports a specific set
-  // of versions.
+  // Optional. The Skaffold version to use when operating on this release, such
+  // as "1.20.0". Not all versions are valid; Cloud Deploy supports a specific
+  // set of versions.
   //
   // If unset, the most recent supported Skaffold version will be used.
-  string skaffold_version = 19;
+  string skaffold_version = 19 [(google.api.field_behavior) = OPTIONAL];
 
   // Output only. Map from target ID to the target artifacts created
   // during the render operation.
@@ -3444,9 +3444,10 @@ message OperationMetadata {
 
   // Output only. Identifies whether the user has requested cancellation
   // of the operation. Operations that have successfully been cancelled
-  // have [Operation.error][] value with a
-  // [google.rpc.Status.code][google.rpc.Status.code] of 1, corresponding to
-  // `Code.CANCELLED`.
+  // have
+  // [google.longrunning.Operation.error][google.longrunning.Operation.error]
+  // value with a [google.rpc.Status.code][google.rpc.Status.code] of 1,
+  // corresponding to `Code.CANCELLED`.
   bool requested_cancellation = 6 [(google.api.field_behavior) = OUTPUT_ONLY];
 
   // Output only. API version used to start the operation.
diff --git a/packages/google-cloud-deploy/protos/protos.json b/packages/google-cloud-deploy/protos/protos.json
index d76558b0530..e1410c6454d 100644
--- a/packages/google-cloud-deploy/protos/protos.json
+++ b/packages/google-cloud-deploy/protos/protos.json
@@ -3281,7 +3281,10 @@
                         },
                         "skaffoldVersion": {
                           "type": "string",
-                          "id": 19
+                          "id": 19,
+                          "options": {
+                            "(google.api.field_behavior)": "OPTIONAL"
+                          }
                         },
                         "targetArtifacts": {
                           "keyType": "string",