diff --git a/Makefile b/Makefile
index cb872aa..1085fd3 100644
--- a/Makefile
+++ b/Makefile
@@ -5,15 +5,15 @@
 generate:
 	if [ -f jni/Makefile ]; then make -C jni generate; fi
 debug: generate
-	./gradlew assembleDebug
+	./gradlew --warning-mode=all assembleDebug bundleDebug
 release: generate
-	./gradlew assembleRelease
+	./gradlew --warning-mode=all assembleRelease bundleRelease
 install: generate
-	./gradlew installDebug
+	./gradlew --warning-mode=all installDebug
 lint:
-	./gradlew lint
+	./gradlew --warning-mode=all lint
 archive: generate
-	./gradlew uploadArchives
+	./gradlew --warning-mode=all uploadArchives
 sync: archive
 	rsync -av MAVEN/com/ ghostscript.com:/var/www/maven.ghostscript.com/com/
 
diff --git a/app/build.gradle b/app/build.gradle
index 5c93439..9d282be 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -4,7 +4,7 @@
 version = '1.16.1'
 
 dependencies {
-	implementation 'com.android.support:appcompat-v7:25.+'
+	implementation 'androidx.appcompat:appcompat:1.1.+'
 	if (file('../lib/build.gradle').isFile())
 		api project(':lib')
 	else
@@ -12,10 +12,10 @@
 }
 
 android {
-	compileSdkVersion 26
+	compileSdkVersion 28
 	defaultConfig {
 		minSdkVersion 16
-		targetSdkVersion 26
+		targetSdkVersion 28
 		versionName '1.16.1'
 		versionCode 70
 	}
@@ -27,13 +27,9 @@
 		}
 	}
 
-	// Increment version code for each ABI variant
-	def abiOffsets = [ 'armeabi-v7a':1, 'arm64-v8a':2, 'x86':3, 'x86_64':4, ]
-	applicationVariants.all { variant ->
-		variant.outputs.each { output ->
-			def offset = abiOffsets.get(output.getFilter(com.android.build.OutputFile.ABI))
-			if (offset != null)
-				output.versionCodeOverride = variant.versionCode + offset
+	bundle {
+		abi {
+			enableSplit true
 		}
 	}
 
diff --git a/app/src/main/java/com/artifex/mupdf/viewer/app/LibraryActivity.java b/app/src/main/java/com/artifex/mupdf/viewer/app/LibraryActivity.java
index dd57166..88dac95 100644
--- a/app/src/main/java/com/artifex/mupdf/viewer/app/LibraryActivity.java
+++ b/app/src/main/java/com/artifex/mupdf/viewer/app/LibraryActivity.java
@@ -13,8 +13,8 @@
 import android.widget.ArrayAdapter;
 import android.widget.ListView;
 
-import android.support.v4.app.ActivityCompat;
-import android.support.v4.content.ContextCompat;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
 
 import java.io.File;
 import java.io.FileFilter;
diff --git a/build.gradle b/build.gradle
index 99228c3..124f6ec 100644
--- a/build.gradle
+++ b/build.gradle
@@ -4,7 +4,7 @@
 		google()
 	}
 	dependencies {
-		classpath 'com.android.tools.build:gradle:3.1.0'
+		classpath 'com.android.tools.build:gradle:3.4.2'
 	}
 }
 
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 94173e9..d282b6b 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.1.1-bin.zip
diff --git a/lib/build.gradle b/lib/build.gradle
index c01f381..fcddbf2 100644
--- a/lib/build.gradle
+++ b/lib/build.gradle
@@ -12,10 +12,10 @@
 }
 
 android {
-	compileSdkVersion 26
+	compileSdkVersion 28
 	defaultConfig {
 		minSdkVersion 16
-		targetSdkVersion 26
+		targetSdkVersion 28
 	}
 }