diff --git a/src/bucket.ts b/src/bucket.ts
index 9eb66ed81..23baca69b 100644
--- a/src/bucket.ts
+++ b/src/bucket.ts
@@ -3269,7 +3269,7 @@ class Bucket extends ServiceObject {
 
     // You aren't allowed to set both predefinedAcl & acl properties on a bucket
     // so acl must explicitly be nullified.
-    const metadata = {...(options.metadata || {}), acl: null};
+    const metadata = {...options.metadata, acl: null};
 
     this.setMetadata(metadata, query, err => {
       if (err) {
@@ -3513,7 +3513,7 @@ class Bucket extends ServiceObject {
     callback?: BodyResponseCallback
   ): void | Promise<[ResponseBody, Metadata]> {
     if (this.userProject && (!reqOpts.qs || !reqOpts.qs.userProject)) {
-      reqOpts.qs = {...(reqOpts.qs || {}), userProject: this.userProject};
+      reqOpts.qs = {...reqOpts.qs, userProject: this.userProject};
     }
     return super.request(reqOpts, callback!);
   }
diff --git a/src/file.ts b/src/file.ts
index f963a5d3e..11fa7f4b3 100644
--- a/src/file.ts
+++ b/src/file.ts
@@ -1150,14 +1150,14 @@ class File extends ServiceObject<File> {
       throw noDestinationError;
     }
 
-    let options: ReadonlyOptions<CopyOptions> = {};
+    let userOptions: ReadonlyOptions<CopyOptions> = {};
     if (typeof optionsOrCallback === 'function') {
       callback = optionsOrCallback;
     } else if (optionsOrCallback) {
-      options = optionsOrCallback;
+      userOptions = optionsOrCallback;
     }
 
-    const payload = {...options};
+    const options = {...userOptions};
 
     callback = callback || util.noop;
 
@@ -1189,16 +1189,16 @@ class File extends ServiceObject<File> {
     if (this.generation !== undefined) {
       query.sourceGeneration = this.generation;
     }
-    if (options.token !== undefined) {
-      query.rewriteToken = options.token;
+    if (userOptions.token !== undefined) {
+      query.rewriteToken = userOptions.token;
     }
-    if (options.userProject !== undefined) {
-      query.userProject = options.userProject;
-      delete payload.userProject;
+    if (userOptions.userProject !== undefined) {
+      query.userProject = userOptions.userProject;
+      delete options.userProject;
     }
-    if (options.predefinedAcl !== undefined) {
-      query.destinationPredefinedAcl = options.predefinedAcl;
-      delete payload.predefinedAcl;
+    if (userOptions.predefinedAcl !== undefined) {
+      query.destinationPredefinedAcl = userOptions.predefinedAcl;
+      delete options.predefinedAcl;
     }
 
     newFile = newFile! || destBucket.file(destName);
@@ -1214,9 +1214,9 @@ class File extends ServiceObject<File> {
 
     if (newFile.encryptionKey !== undefined) {
       this.setEncryptionKey(newFile.encryptionKey!);
-    } else if (options.destinationKmsKeyName !== undefined) {
-      query.destinationKmsKeyName = options.destinationKmsKeyName;
-      delete payload.destinationKmsKeyName;
+    } else if (userOptions.destinationKmsKeyName !== undefined) {
+      query.destinationKmsKeyName = userOptions.destinationKmsKeyName;
+      delete options.destinationKmsKeyName;
     } else if (newFile.kmsKeyName !== undefined) {
       query.destinationKmsKeyName = newFile.kmsKeyName;
     }
@@ -1234,15 +1234,15 @@ class File extends ServiceObject<File> {
 
     if (
       !this.shouldRetryBasedOnPreconditionAndIdempotencyStrat(
-        options?.preconditionOpts
+        userOptions?.preconditionOpts
       )
     ) {
       this.storage.retryOptions.autoRetry = false;
     }
 
-    if (options.preconditionOpts?.ifGenerationMatch !== undefined) {
-      query.ifGenerationMatch = options.preconditionOpts?.ifGenerationMatch;
-      delete payload.preconditionOpts;
+    if (userOptions.preconditionOpts?.ifGenerationMatch !== undefined) {
+      query.ifGenerationMatch = userOptions.preconditionOpts?.ifGenerationMatch;
+      delete options.preconditionOpts;
     }
 
     this.request(
@@ -1252,7 +1252,7 @@ class File extends ServiceObject<File> {
           newFile.name
         )}`,
         qs: query,
-        json: payload,
+        json: options,
         headers,
       },
       (err, resp) => {
@@ -3072,7 +3072,6 @@ class File extends ServiceObject<File> {
     // You aren't allowed to set both predefinedAcl & acl properties on a file,
     // so acl must explicitly be nullified, destroying all previous acls on the
     // file.
-
     const metadata = {...options.metadata, acl: null};
 
     this.setMetadata(metadata, query, callback!);
diff --git a/src/nodejs-common/service-object.ts b/src/nodejs-common/service-object.ts
index f739a2383..37b6ae262 100644
--- a/src/nodejs-common/service-object.ts
+++ b/src/nodejs-common/service-object.ts
@@ -507,7 +507,10 @@ class ServiceObject<T = any> extends EventEmitter {
       method: 'PATCH',
       uri: '',
       ...methodConfig.reqOpts,
-      json: {...metadata} as ReadonlyOptions<Metadata>,
+      json: {
+        ...methodConfig.reqOpts?.json,
+        ...metadata,
+      } as ReadonlyOptions<Metadata>,
       qs: {
         ...methodConfig.reqOpts?.qs,
         ...options,
diff --git a/src/nodejs-common/util.ts b/src/nodejs-common/util.ts
index 8f70820a3..35db154a1 100644
--- a/src/nodejs-common/util.ts
+++ b/src/nodejs-common/util.ts
@@ -400,7 +400,7 @@ export class Util {
     callback = callback || util.noop;
 
     const parsedResp = {
-      err: err || undefined,
+      err: err || null,
       ...(resp && util.parseHttpRespMessage(resp)),
       ...(body && util.parseHttpRespBody(body)),
     };
@@ -515,6 +515,10 @@ export class Util {
     const reqOpts = {
       ...defaultReqOpts,
       ...options.request,
+      qs: {
+        ...defaultReqOpts.qs,
+        ...options.request?.qs,
+      },
       multipart: [
         {
           'Content-Type': 'application/json',
diff --git a/src/resumable-upload.ts b/src/resumable-upload.ts
index cbfa6531c..4593d5e46 100644
--- a/src/resumable-upload.ts
+++ b/src/resumable-upload.ts
@@ -958,7 +958,12 @@ export class Upload extends Writable {
     const combinedReqOpts = {
       ...this.customRequestOptions,
       ...reqOpts,
+      headers: {
+        ...this.customRequestOptions.headers,
+        ...reqOpts.headers,
+      },
     };
+
     const res = await this.authClient.request<{error?: object}>(
       combinedReqOpts
     );
@@ -983,6 +988,10 @@ export class Upload extends Writable {
     const combinedReqOpts = {
       ...this.customRequestOptions,
       ...reqOpts,
+      headers: {
+        ...this.customRequestOptions.headers,
+        ...reqOpts.headers,
+      },
     };
     const res = await this.authClient.request(combinedReqOpts);
     const successfulRequest = this.onResponse(res);