diff --git a/tools/errorprone/errorprone.gradle b/tools/errorprone/errorprone.gradle
index e7a329ccf2a..14706959d1b 100644
--- a/tools/errorprone/errorprone.gradle
+++ b/tools/errorprone/errorprone.gradle
@@ -18,6 +18,7 @@ apply plugin: 'java-library'
 dependencies {
     implementation 'com.google.errorprone:error_prone_check_api:2.3.2'
     implementation 'com.google.auto.service:auto-service:1.0-rc4'
+    annotationProcessor 'com.google.auto.service:auto-service:1.0-rc4'
 
     testImplementation 'junit:junit:4.12'
     testImplementation 'com.google.errorprone:error_prone_test_helpers:2.3.1'