diff --git a/src/grpc.ts b/src/grpc.ts
index dfca09aea..f20e209da 100644
--- a/src/grpc.ts
+++ b/src/grpc.ts
@@ -78,7 +78,6 @@ export interface Metadata {
 
 export type GrpcModule = typeof grpcTypes&{
   status: {[index: string]: number;};
-  isLegacy: boolean;
 };
 
 export interface ClientStubOptions {
@@ -128,11 +127,9 @@ export class GrpcClient {
       if (semver.gte(process.version, '8.13.0') &&
           !!process.env.GOOGLE_CLOUD_USE_GRPC_JS) {
         this.grpc = require('@grpc/grpc-js');
-        this.grpc.isLegacy = false;
         this.grpcVersion = require('@grpc/grpc-js/package.json').version;
       } else {
         this.grpc = require('grpc');
-        this.grpc.isLegacy = true;
         this.grpcVersion = require('grpc/package.json').version;
       }
     }
@@ -172,28 +169,13 @@ export class GrpcClient {
 
   /**
    * Load grpc proto service from a filename hooking in googleapis common protos
-   * when necessary. Uses legacy grpc.loadObject.
+   * when necessary.
    * @param {String} protoPath - The directory to search for the protofile.
    * @param {String} filename - The filename of the proto to be loaded.
    * @return {Object<string, *>} The gRPC loaded result (the toplevel namespace
    *   object).
    */
-  protected loadProtoLegacy(protoPath: string, filename: string) {
-    const resolvedPath = GrpcClient._resolveFile(protoPath, filename);
-    const retval = this.grpc.loadObject(
-        protobuf.loadSync(resolvedPath, new GoogleProtoFilesRoot()));
-    return retval;
-  }
-
-  /**
-   * Load grpc proto service from a filename hooking in googleapis common protos
-   * when necessary. Uses the new shiny @grpc/proto-loader.
-   * @param {String} protoPath - The directory to search for the protofile.
-   * @param {String} filename - The filename of the proto to be loaded.
-   * @return {Object<string, *>} The gRPC loaded result (the toplevel namespace
-   *   object).
-   */
-  protected loadProtoGrpcJs(protoPath: string, filename: string) {
+  loadProto(protoPath: string, filename: string) {
     // This set of @grpc/proto-loader options
     // 'closely approximates the existing behavior of grpc.load'
     const includeDirs = INCLUDE_DIRS.slice();
@@ -209,20 +191,6 @@ export class GrpcClient {
     return this.loadFromProto(filename, options);
   }
 
-  /**
-   * Load grpc proto service from a filename hooking in googleapis common protos
-   * when necessary. Can use either legacy grpc.loadProto, or new
-   * @grpc/proto-loader, depending on which gRPC backend is used.
-   * @param {String} protoPath - The directory to search for the protofile.
-   * @param {String} filename - The filename of the proto to be loaded.
-   * @return {Object<string, *>} The gRPC loaded result (the toplevel namespace
-   *   object).
-   */
-  loadProto(protoPath: string, filename: string) {
-    return this.grpc.isLegacy ? this.loadProtoLegacy(protoPath, filename) :
-                                this.loadProtoGrpcJs(protoPath, filename);
-  }
-
   static _resolveFile(protoPath: string, filename: string) {
     if (fs.existsSync(path.join(protoPath, filename))) {
       return path.join(protoPath, filename);