diff --git a/samples/generated/v1/device_manager.get_iam_policy.js b/samples/generated/v1/device_manager.get_iam_policy.js
index 2bbdc4c5..039b3941 100644
--- a/samples/generated/v1/device_manager.get_iam_policy.js
+++ b/samples/generated/v1/device_manager.get_iam_policy.js
@@ -32,7 +32,7 @@ function main(resource) {
   // const resource = 'abc123'
   /**
    *  OPTIONAL: A `GetPolicyOptions` object for specifying options to
-   *  `GetIamPolicy`. This field is only used by Cloud IAM.
+   *  `GetIamPolicy`.
    */
   // const options = {}
 
diff --git a/samples/generated/v1/device_manager.set_iam_policy.js b/samples/generated/v1/device_manager.set_iam_policy.js
index 69a8c763..05ba74e3 100644
--- a/samples/generated/v1/device_manager.set_iam_policy.js
+++ b/samples/generated/v1/device_manager.set_iam_policy.js
@@ -37,6 +37,13 @@ function main(resource, policy) {
    *  might reject them.
    */
   // const policy = {}
+  /**
+   *  OPTIONAL: A FieldMask specifying which fields of the policy to modify. Only
+   *  the fields in the mask will be modified. If no mask is provided, the
+   *  following default mask is used:
+   *  `paths: "bindings, etag"`
+   */
+  // const updateMask = {}
 
   // Imports the Iot library
   const {DeviceManagerClient} = require('@google-cloud/iot').v1;
diff --git a/samples/generated/v1/snippet_metadata.google.cloud.iot.v1.json b/samples/generated/v1/snippet_metadata.google.cloud.iot.v1.json
index 74f68c7c..f70dc8b9 100644
--- a/samples/generated/v1/snippet_metadata.google.cloud.iot.v1.json
+++ b/samples/generated/v1/snippet_metadata.google.cloud.iot.v1.json
@@ -610,7 +610,7 @@
       "segments": [
         {
           "start": 25,
-          "end": 59,
+          "end": 66,
           "type": "FULL"
         }
       ],
@@ -626,6 +626,10 @@
           {
             "name": "policy",
             "type": ".google.iam.v1.Policy"
+          },
+          {
+            "name": "update_mask",
+            "type": ".google.protobuf.FieldMask"
           }
         ],
         "resultType": ".google.iam.v1.Policy",
diff --git a/src/v1/device_manager_client.ts b/src/v1/device_manager_client.ts
index c22f5c4a..b73c1164 100644
--- a/src/v1/device_manager_client.ts
+++ b/src/v1/device_manager_client.ts
@@ -1387,6 +1387,12 @@ export class DeviceManagerClient {
    *   the policy is limited to a few 10s of KB. An empty policy is a
    *   valid policy but certain Cloud Platform services (such as Projects)
    *   might reject them.
+   * @param {google.protobuf.FieldMask} request.updateMask
+   *   OPTIONAL: A FieldMask specifying which fields of the policy to modify. Only
+   *   the fields in the mask will be modified. If no mask is provided, the
+   *   following default mask is used:
+   *
+   *   `paths: "bindings, etag"`
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.
@@ -1475,7 +1481,7 @@ export class DeviceManagerClient {
    *   See the operation documentation for the appropriate value for this field.
    * @param {google.iam.v1.GetPolicyOptions} request.options
    *   OPTIONAL: A `GetPolicyOptions` object for specifying options to
-   *   `GetIamPolicy`. This field is only used by Cloud IAM.
+   *   `GetIamPolicy`.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.