diff --git a/mace/examples/android/app/build.gradle b/mace/examples/android/app/build.gradle
index 0e4d948e80ac3a865536028274dcd900d095871a..a1f68ed3266e21b7f45cd128db5f668fbaa813c1 100644
--- a/mace/examples/android/app/build.gradle
+++ b/mace/examples/android/app/build.gradle
@@ -4,7 +4,7 @@ android {
     compileSdkVersion 26
     defaultConfig {
         applicationId "com.xiaomi.mace.demo"
-        minSdkVersion 19
+        minSdkVersion 21
         targetSdkVersion 26
         versionCode 1
         versionName "1.0"
diff --git a/mace/examples/android/macelibrary/build.gradle b/mace/examples/android/macelibrary/build.gradle
index 2f25f01728428faf03a648f72b7b70ddec3b2824..891ad5b7584c16408011fb03758c1ed8d2dafa88 100644
--- a/mace/examples/android/macelibrary/build.gradle
+++ b/mace/examples/android/macelibrary/build.gradle
@@ -9,14 +9,14 @@ android {
     }
 
     defaultConfig {
-        minSdkVersion 19
+        minSdkVersion 21
         targetSdkVersion 26
         versionCode 1
         versionName "1.0"
 
         externalNativeBuild {
             cmake {
-                cppFlags "-std=c++14 -fopenmp"
+                cppFlags "-std=c++11 -fopenmp"
                 abiFilters "arm64-v8a"
             }
         }