diff --git a/android/build.gradle b/android/build.gradle
index e148609..ced7c4f 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -13,13 +13,17 @@ buildscript {
 
 apply plugin: 'com.android.library'
 
+def safeExtGet(prop, fallback) {
+    rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
+}
+
 android {
-    compileSdkVersion 27
-    buildToolsVersion '28.0.3'
+    compileSdkVersion safeExtGet("compileSdkVersion", 27)
+    buildToolsVersion safeExtGet("buildToolsVersion", "28.0.3")
 
     defaultConfig {
-        minSdkVersion 16
-        targetSdkVersion 27
+        minSdkVersion safeExtGet("minSdkVersion", 16)
+        targetSdkVersion safeExtGet("targetSdkVersion", 27)
         versionCode 1
         versionName "1.0"
     }