Import Protobuf generated classes using Gradle in IntelliJ

I am having trouble importing Protobuf generated classes using Gradle.

This is how my project tree looks like:

I've tried marking the packages as Source, I have tried all possible combinations of imports:

import generated.main.grpc.GreeterGrpc;
import main.java.HelloRequest;
import java.*;
import HelloRequest;

None of them works. Here is my build.gradle:

group 'andu'
version '1.0-SNAPSHOT'

apply plugin: 'java'
apply plugin: 'com.google.protobuf'

sourceCompatibility = 1.5

repositories {
    mavenCentral()
    maven { url "https://plugins.gradle.org/m2/" }
}

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.0'
    }
}

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.11'
    compile 'io.grpc:grpc-protobuf:1.0.0-pre2'
    compile 'com.google.protobuf:protobuf-java:3.0.0'
    compile 'io.grpc:grpc-stub:1.0.0-pre2'
    compile 'io.grpc:grpc-netty:1.3.0'
    compile 'io.grpc:grpc-protobuf:1.3.0'
    compile 'io.grpc:grpc-stub:1.3.0'
}



sourceSets {
    main {
        proto {
            srcDir 'src/main/proto'
        }
        java {
            srcDirs =  ['src/main/java', 'generated/main/java']
        }
    }
}

protobuf {
    protoc {
        artifact = "com.google.protobuf:protoc:3.2.0"
    }
    plugins {
        grpc {
            artifact = 'io.grpc:protoc-gen-grpc-java:1.3.0'
        }
    }

    generateProtoTasks.generatedFilesBaseDir = 'generated'

    generateProtoTasks {
        all()*.plugins {
            grpc {}
        }
    }
}

Before I added

generateProtoTasks.generatedFilesBaseDir = 'generated'

all of my generated classes would be added to build/generated/main/java