diff --git a/apng_library/build.gradle b/apng_library/build.gradle
index d4ec488..12d814e 100644
--- a/apng_library/build.gradle
+++ b/apng_library/build.gradle
@@ -6,7 +6,7 @@ android {
     compileSdkVersion 29
 
     defaultConfig {
-        minSdkVersion 21
+        minSdkVersion 19
         targetSdkVersion 29
         versionCode 1
         versionName "1.0.10-beta2"
diff --git a/app-test/build.gradle b/app-test/build.gradle
index 9eefeae..2c134c2 100644
--- a/app-test/build.gradle
+++ b/app-test/build.gradle
@@ -7,7 +7,7 @@ android {
 
     defaultConfig {
         applicationId "oupson.apngcreator"
-        minSdkVersion 21
+        minSdkVersion 19
         targetSdkVersion 29
         versionCode 1
         versionName "1.0.10-beta2"