diff --git a/app/build.gradle b/app/build.gradle
index 14b2299..795325d 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -27,6 +27,7 @@
     implementation fileTree(include: ['*.jar'], dir: 'libs')
     implementation 'com.android.support:appcompat-v7:27.1.1'
     implementation 'com.android.support.constraint:constraint-layout:1.1.0'
+    implementation 'com.android.support:support-v4:27.1.1'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'