diff --git a/packages/google-cloud-dataproc/protos/google/cloud/dataproc/v1/clusters.proto b/packages/google-cloud-dataproc/protos/google/cloud/dataproc/v1/clusters.proto
index fbaf9391ed0..c66d35d372f 100644
--- a/packages/google-cloud-dataproc/protos/google/cloud/dataproc/v1/clusters.proto
+++ b/packages/google-cloud-dataproc/protos/google/cloud/dataproc/v1/clusters.proto
@@ -111,8 +111,8 @@ service ClusterController {
     };
     option (google.api.method_signature) = "project_id,region,cluster_name";
     option (google.longrunning.operation_info) = {
-      response_type: "google.protobuf.Empty"
-      metadata_type: "DiagnoseClusterResults"
+      response_type: "DiagnoseClusterResults"
+      metadata_type: "google.cloud.dataproc.v1.ClusterOperationMetadata"
     };
   }
 }
diff --git a/packages/google-cloud-dataproc/protos/protos.json b/packages/google-cloud-dataproc/protos/protos.json
index f3ae571ec27..a5d00d876dc 100644
--- a/packages/google-cloud-dataproc/protos/protos.json
+++ b/packages/google-cloud-dataproc/protos/protos.json
@@ -362,8 +362,8 @@
                             "(google.api.http).post": "/v1/projects/{project_id}/regions/{region}/clusters/{cluster_name}:diagnose",
                             "(google.api.http).body": "*",
                             "(google.api.method_signature)": "project_id,region,cluster_name",
-                            "(google.longrunning.operation_info).response_type": "google.protobuf.Empty",
-                            "(google.longrunning.operation_info).metadata_type": "DiagnoseClusterResults"
+                            "(google.longrunning.operation_info).response_type": "DiagnoseClusterResults",
+                            "(google.longrunning.operation_info).metadata_type": "google.cloud.dataproc.v1.ClusterOperationMetadata"
                           }
                         }
                       }
diff --git a/packages/google-cloud-dataproc/src/v1/cluster_controller_client.ts b/packages/google-cloud-dataproc/src/v1/cluster_controller_client.ts
index 7ce1d34b2d5..c7e6969e937 100644
--- a/packages/google-cloud-dataproc/src/v1/cluster_controller_client.ts
+++ b/packages/google-cloud-dataproc/src/v1/cluster_controller_client.ts
@@ -223,10 +223,10 @@ export class ClusterControllerClient {
       '.google.cloud.dataproc.v1.ClusterOperationMetadata'
     ) as gax.protobuf.Type;
     const diagnoseClusterResponse = protoFilesRoot.lookup(
-      '.google.protobuf.Empty'
+      '.google.cloud.dataproc.v1.DiagnoseClusterResults'
     ) as gax.protobuf.Type;
     const diagnoseClusterMetadata = protoFilesRoot.lookup(
-      '.google.cloud.dataproc.v1.DiagnoseClusterResults'
+      '.google.cloud.dataproc.v1.ClusterOperationMetadata'
     ) as gax.protobuf.Type;
 
     this.descriptors.longrunning = {
@@ -1001,8 +1001,8 @@ export class ClusterControllerClient {
   ): Promise<
     [
       LROperation<
-        protos.google.protobuf.IEmpty,
-        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults
+        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults,
+        protos.google.cloud.dataproc.v1.IClusterOperationMetadata
       >,
       protos.google.longrunning.IOperation | undefined,
       {} | undefined
@@ -1013,8 +1013,8 @@ export class ClusterControllerClient {
     options: gax.CallOptions,
     callback: Callback<
       LROperation<
-        protos.google.protobuf.IEmpty,
-        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults
+        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults,
+        protos.google.cloud.dataproc.v1.IClusterOperationMetadata
       >,
       protos.google.longrunning.IOperation | null | undefined,
       {} | null | undefined
@@ -1024,8 +1024,8 @@ export class ClusterControllerClient {
     request: protos.google.cloud.dataproc.v1.IDiagnoseClusterRequest,
     callback: Callback<
       LROperation<
-        protos.google.protobuf.IEmpty,
-        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults
+        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults,
+        protos.google.cloud.dataproc.v1.IClusterOperationMetadata
       >,
       protos.google.longrunning.IOperation | null | undefined,
       {} | null | undefined
@@ -1061,16 +1061,16 @@ export class ClusterControllerClient {
       | gax.CallOptions
       | Callback<
           LROperation<
-            protos.google.protobuf.IEmpty,
-            protos.google.cloud.dataproc.v1.IDiagnoseClusterResults
+            protos.google.cloud.dataproc.v1.IDiagnoseClusterResults,
+            protos.google.cloud.dataproc.v1.IClusterOperationMetadata
           >,
           protos.google.longrunning.IOperation | null | undefined,
           {} | null | undefined
         >,
     callback?: Callback<
       LROperation<
-        protos.google.protobuf.IEmpty,
-        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults
+        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults,
+        protos.google.cloud.dataproc.v1.IClusterOperationMetadata
       >,
       protos.google.longrunning.IOperation | null | undefined,
       {} | null | undefined
@@ -1078,8 +1078,8 @@ export class ClusterControllerClient {
   ): Promise<
     [
       LROperation<
-        protos.google.protobuf.IEmpty,
-        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults
+        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults,
+        protos.google.cloud.dataproc.v1.IClusterOperationMetadata
       >,
       protos.google.longrunning.IOperation | undefined,
       {} | undefined
@@ -1122,8 +1122,8 @@ export class ClusterControllerClient {
     name: string
   ): Promise<
     LROperation<
-      protos.google.protobuf.Empty,
-      protos.google.cloud.dataproc.v1.DiagnoseClusterResults
+      protos.google.cloud.dataproc.v1.DiagnoseClusterResults,
+      protos.google.cloud.dataproc.v1.ClusterOperationMetadata
     >
   > {
     const request = new operationsProtos.google.longrunning.GetOperationRequest(
@@ -1136,8 +1136,8 @@ export class ClusterControllerClient {
       gax.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
-      protos.google.protobuf.Empty,
-      protos.google.cloud.dataproc.v1.DiagnoseClusterResults
+      protos.google.cloud.dataproc.v1.DiagnoseClusterResults,
+      protos.google.cloud.dataproc.v1.ClusterOperationMetadata
     >;
   }
   listClusters(
diff --git a/packages/google-cloud-dataproc/synth.metadata b/packages/google-cloud-dataproc/synth.metadata
index 5f96db0251a..801ba219647 100644
--- a/packages/google-cloud-dataproc/synth.metadata
+++ b/packages/google-cloud-dataproc/synth.metadata
@@ -4,15 +4,15 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/nodejs-dataproc.git",
-        "sha": "7654222e12f9152acfbf7b4f6ccaeabb4e8aed2e"
+        "sha": "9ffa8085dbbafe55bf21a49bff50e88a0b819e11"
       }
     },
     {
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "4f4aa3a03e470f1390758b9d89eb1aa88837a5be",
-        "internalRef": "320300472"
+        "sha": "0e7900e3950d32ccafae22a2ccb85fa61ffe08f9",
+        "internalRef": "321255718"
       }
     },
     {
diff --git a/packages/google-cloud-dataproc/test/gapic_cluster_controller_v1.ts b/packages/google-cloud-dataproc/test/gapic_cluster_controller_v1.ts
index 6418946d9bf..8ce3209df52 100644
--- a/packages/google-cloud-dataproc/test/gapic_cluster_controller_v1.ts
+++ b/packages/google-cloud-dataproc/test/gapic_cluster_controller_v1.ts
@@ -993,8 +993,8 @@ describe('v1.ClusterControllerClient', () => {
           (
             err?: Error | null,
             result?: LROperation<
-              protos.google.protobuf.IEmpty,
-              protos.google.cloud.dataproc.v1.IDiagnoseClusterResults
+              protos.google.cloud.dataproc.v1.IDiagnoseClusterResults,
+              protos.google.cloud.dataproc.v1.IClusterOperationMetadata
             > | null
           ) => {
             if (err) {
@@ -1006,8 +1006,8 @@ describe('v1.ClusterControllerClient', () => {
         );
       });
       const operation = (await promise) as LROperation<
-        protos.google.protobuf.IEmpty,
-        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults
+        protos.google.cloud.dataproc.v1.IDiagnoseClusterResults,
+        protos.google.cloud.dataproc.v1.IClusterOperationMetadata
       >;
       const [response] = await operation.promise();
       assert.deepStrictEqual(response, expectedResponse);