diff --git a/Live/build.gradle b/Live/build.gradle
index 09cbd28..fce0861 100644
--- a/Live/build.gradle
+++ b/Live/build.gradle
@@ -33,5 +33,5 @@ android {
 
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
-    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation "androidx.appcompat:appcompat:$rootProject.appcompatVersion"
 }
diff --git a/OnLive/build.gradle b/OnLive/build.gradle
index be8a324..e01a34a 100644
--- a/OnLive/build.gradle
+++ b/OnLive/build.gradle
@@ -39,14 +39,14 @@ android {
 
 dependencies {
     implementation fileTree(include: ['*.jar'], dir: 'libs')
-    implementation 'androidx.appcompat:appcompat:1.1.0'
-    implementation 'androidx.preference:preference:1.1.0'
-    implementation 'androidx.annotation:annotation:1.1.0'
-    implementation 'androidx.recyclerview:recyclerview:1.1.0-rc01'
+    implementation "androidx.appcompat:appcompat:$rootProject.appcompatVersion"
+    implementation "androidx.preference:preference:$rootProject.preferenceVersion"
+    implementation "androidx.annotation:annotation:$rootProject.annotationVersion"
+    implementation "androidx.recyclerview:recyclerview:$rootProject.recyclerviewVersion"
 
-    implementation 'com.squareup:otto:1.3.8'
+    implementation "com.squareup:otto:$rootProject.ottoVersion"
 
-    implementation 'tv.danmaku.ijk.media:ijkplayer-java:0.8.8'
-    implementation 'tv.danmaku.ijk.media:ijkplayer-exo:0.8.8'
+    implementation "tv.danmaku.ijk.media:ijkplayer-java:$rootProject.ijkVersion"
+    implementation "tv.danmaku.ijk.media:ijkplayer-exo:$rootProject.ijkVersion"
 
 }
diff --git a/app/build.gradle b/app/build.gradle
index 599de3c..7058e14 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -42,8 +42,8 @@ android {
 
 dependencies {
     implementation fileTree(include: ['*.jar'], dir: 'libs')
-    implementation 'androidx.appcompat:appcompat:1.1.0'
-    implementation 'androidx.recyclerview:recyclerview:1.1.0-rc01'
+    implementation "androidx.appcompat:appcompat:$rootProject.appcompatVersion"
+    implementation "androidx.recyclerview:recyclerview:$rootProject.recyclerviewVersion"
     testImplementation 'junit:junit:4.12'
     implementation project(':Live')
 }
diff --git a/gradle.properties b/gradle.properties
index fe01dc1..2fd727c 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -18,3 +18,10 @@
 org.gradle.jvmargs=-Xmx512m
 android.enableJetifier=true
 android.useAndroidX=true
+
+appcompatVersion=1.1.0
+recyclerviewVersion=1.1.0-rc01
+preferenceVersion=1.1.0
+annotationVersion=1.1.0
+ottoVersion=1.3.8
+ijkVersion=0.8.8
\ No newline at end of file