diff --git a/sample_client/build.gradle b/sample_client/build.gradle
index 7f865ceb..b41ff109 100644
--- a/sample_client/build.gradle
+++ b/sample_client/build.gradle
@@ -8,7 +8,7 @@ android {
     compileSdkVersion 28
 
     defaultConfig {
-        minSdkVersion 19
+        minSdkVersion 21
         targetSdkVersion 28
     }