diff --git a/build.gradle b/build.gradle
index c67eb3b..de6b1ac 100644
--- a/build.gradle
+++ b/build.gradle
@@ -25,7 +25,7 @@ allprojects {
 android {
     buildToolsVersion '27.0.0'
     defaultConfig {
-        minSdkVersion 26
+        minSdkVersion 21
         targetSdkVersion 27
         testInstrumentationRunner 'android.test.InstrumentationTestRunner'
         multiDexEnabled true