diff --git a/library/build.gradle b/library/build.gradle
index 97bd2fb..ac5e879 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -27,8 +27,8 @@ android {
     }
 
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_8
-        targetCompatibility JavaVersion.VERSION_1_8
+        sourceCompatibility JavaVersion.VERSION_1_7
+        targetCompatibility JavaVersion.VERSION_1_7
     }
 }
 
@@ -42,6 +42,6 @@ dependencies {
     testCompile 'junit:junit:4.12'
     compile 'com.android.support:support-annotations:25.2.0'
     compile 'com.google.code.gson:gson:2.7'
-    compile 'com.google.guava:guava:21.0'
+    compile 'com.google.guava:guava:20.0'
     compile 'com.android.volley:volley:1.0.0'
 }