diff --git a/core/build.gradle b/core/build.gradle
index af1ac7ad0..de156d7c7 100644
--- a/core/build.gradle
+++ b/core/build.gradle
@@ -49,6 +49,8 @@ repositories {
 dependencies {
     implementation "com.android.support:support-v4:$supportVersion"
     implementation "com.android.support:appcompat-v7:$supportVersion"
+    implementation "com.android.support:preference-v14:$supportVersion"
+    implementation "com.android.support:percent:$supportVersion"
     implementation "org.apache.commons:commons-lang3:$commonslangVersion"
     implementation "org.apache.commons:commons-text:$commonstextVersion"
     implementation ("org.shredzone.flattr4j:flattr4j-core:$flattr4jVersion") {