diff --git a/sop-java/build.gradle b/sop-java/build.gradle
index c958610..ca546bf 100644
--- a/sop-java/build.gradle
+++ b/sop-java/build.gradle
@@ -19,6 +19,10 @@ dependencies {
     testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junitVersion"
     testFixturesImplementation "org.junit.jupiter:junit-jupiter-api:$junitVersion"
     testFixturesImplementation "org.junit.jupiter:junit-jupiter-params:$junitVersion"
+
+    // @Nullable, @Nonnull annotations
+    implementation "com.google.code.findbugs:jsr305:3.0.2"
+
 }
 
 test {