diff --git a/tutorials/java/Polygons/app/build.gradle b/tutorials/java/Polygons/app/build.gradle
index 0026fc2c..48ff2bb8 100644
--- a/tutorials/java/Polygons/app/build.gradle
+++ b/tutorials/java/Polygons/app/build.gradle
@@ -41,7 +41,7 @@ dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'androidx.appcompat:appcompat:1.2.0'
     implementation 'com.google.android.gms:play-services-maps:17.0.0'
-    testImplementation 'junit:junit:4.13'
+    testImplementation 'junit:junit:4.13.1'
     androidTestImplementation 'androidx.test.ext:junit:1.1.2'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
 }