diff --git a/app/build.gradle b/app/build.gradle
index 59410a3..4cb4b57 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,11 +1,11 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 26
-    buildToolsVersion '28.0.2'
+    compileSdkVersion 29
+    buildToolsVersion '29.0.2'
     defaultConfig {
         minSdkVersion 9
-        targetSdkVersion 26
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
     }
diff --git a/time4j-android/build.gradle b/time4j-android/build.gradle
index 243ac24..f202293 100644
--- a/time4j-android/build.gradle
+++ b/time4j-android/build.gradle
@@ -33,12 +33,12 @@ gradle.projectsEvaluated {
 }
 
 android {
-    compileSdkVersion 26
-    buildToolsVersion '28.0.2'
+    compileSdkVersion 29
+    buildToolsVersion '29.0.2'
 
     defaultConfig {
         minSdkVersion 9
-        targetSdkVersion 26
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
         consumerProguardFiles 'consumer-proguard-rules.pro'