diff --git a/app/build.gradle b/app/build.gradle
index 29fc784..7dd47a2 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -6,7 +6,7 @@ android {
 
     defaultConfig {
         applicationId "net.ossrs.yasea.demo"
-        minSdkVersion 16
+        minSdkVersion 21
         targetSdkVersion 22
         versionCode 1
         versionName "2.6"
diff --git a/library/build.gradle b/library/build.gradle
index 29646ce..cf3b864 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -5,7 +5,7 @@ android {
     buildToolsVersion "26.0.2"
 
     defaultConfig {
-        minSdkVersion 16
+        minSdkVersion 21
         targetSdkVersion 22
         versionCode 1
         versionName "2.6"