diff --git a/android/build.gradle b/android/build.gradle
index 8a4bbf8..e861599 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -1,6 +1,10 @@
 group 'com.agora.iris_method_channel'
 version '1.0'
 
+def safeExtGet(prop, fallback) {
+    rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
+}
+
 buildscript {
     repositories {
         google()
@@ -27,7 +31,7 @@ android {
         namespace 'com.agora.iris_method_channel'
     }
 
-    compileSdkVersion 31
+    compileSdkVersion safeExtGet('compileSdkVersion', 31)
 
     externalNativeBuild {
         cmake {
@@ -49,7 +53,7 @@ android {
     }
 
     defaultConfig {
-        minSdkVersion 16
+        minSdkVersion safeExtGet('minSdkVersion', 21)
 
         externalNativeBuild {
             cmake {
diff --git a/example/android/app/build.gradle b/example/android/app/build.gradle
index 7ee3157..05c2af5 100644
--- a/example/android/app/build.gradle
+++ b/example/android/app/build.gradle
@@ -38,7 +38,7 @@ android {
         applicationId "com.agora.iris_method_channel_example"
         // You can update the following values to match your application needs. 
         // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-build-configuration.
-        minSdkVersion flutter.minSdkVersion
+        minSdkVersion 21
         targetSdkVersion flutter.targetSdkVersion
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName