diff --git a/build.gradle b/build.gradle
index 887ac6f..c15d55f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -3,7 +3,7 @@ apply plugin: 'me.tatarka.retrolambda'
 
 android {
     compileSdkVersion 26
-    buildToolsVersion '26.0.2'
+    buildToolsVersion buildTools
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -16,7 +16,7 @@ android {
 }
 
 dependencies {
-    provided 'com.android.support:support-annotations:26.0.1'
-    provided 'io.reactivex.rxjava2:rxandroid:2.0.1'
-    provided 'io.reactivex.rxjava2:rxjava:2.1.4'
+    provided "com.android.support:support-annotations:$supportLibraryVersion"
+    provided "io.reactivex.rxjava2:rxandroid:$rxAndroidVersion"
+    provided "io.reactivex.rxjava2:rxjava:$rxJavaVersion"
 }