diff --git a/src/Xamarin.Android.Build.Debugging.Tasks/Tasks/DetectIfAppWasUninstalled.cs b/src/Xamarin.Android.Build.Debugging.Tasks/Tasks/DetectIfAppWasUninstalled.cs
index 1bb2bce2d92..be58ecfbfb5 100644
--- a/src/Xamarin.Android.Build.Debugging.Tasks/Tasks/DetectIfAppWasUninstalled.cs
+++ b/src/Xamarin.Android.Build.Debugging.Tasks/Tasks/DetectIfAppWasUninstalled.cs
@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -14,15 +15,15 @@ public class DetectIfAppWasUninstalled : AndroidTask, ICancelableTask {
 		CancellationTokenSource tcs = new CancellationTokenSource ();
 		public override string TaskPrefix => "DIAWI";
 
-		public string AdbTarget { get; set; }
+		public string? AdbTarget { get; set; }
 
 		[Required]
-		public string PackageName { get; set; }
+		public string PackageName { get; set; } = "";
 
 		[Required]
-		public string UploadFlagFile { get; set; }
+		public string UploadFlagFile { get; set; } = "";
 
-		public string UserID { get; set; }
+		public string? UserID { get; set; }
 
 		public CancellationToken Token { get { return tcs.Token; } }
 
@@ -57,7 +58,7 @@ public override bool RunTask()
 		}
 
 
-		async System.Threading.Tasks.Task<List<AndroidInstalledPackage>> QueryPackages (AndroidDevice device, string uploadFlagFileFullPath)
+		async System.Threading.Tasks.Task<List<AndroidInstalledPackage>?> QueryPackages (AndroidDevice device, string uploadFlagFileFullPath)
 		{
 			// DO NOT use the Log.XXXX methods in this method.
 			// Because this is running on a background thread they will