diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo.Abp.BackgroundJobs.csproj b/framework/src/Volo.Abp.BackgroundJobs/Volo.Abp.BackgroundJobs.csproj
index 0ef692a9f2..29a4ed2edc 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo.Abp.BackgroundJobs.csproj
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo.Abp.BackgroundJobs.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.BackgroundJobs</AssemblyName>
     <PackageId>Volo.Abp.BackgroundJobs</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobInfo.cs b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobInfo.cs
index deba940d12..0d5441a4bc 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobInfo.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobInfo.cs
@@ -12,12 +12,12 @@ public class BackgroundJobInfo
     /// <summary>
     /// Name of the job.
     /// </summary>
-    public virtual string JobName { get; set; }
+    public virtual string JobName { get; set; } = default!;
 
     /// <summary>
     /// Job arguments as serialized to string.
     /// </summary>
-    public virtual string JobArgs { get; set; }
+    public virtual string JobArgs { get; set; } = default!;
 
     /// <summary>
     /// Try count of this job.
diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs
index a222f91362..7218776cfe 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs
@@ -32,7 +32,7 @@ public class DefaultBackgroundJobManager : IBackgroundJobManager, ITransientDepe
     public virtual async Task<string> EnqueueAsync<TArgs>(TArgs args, BackgroundJobPriority priority = BackgroundJobPriority.Normal, TimeSpan? delay = null)
     {
         var jobName = BackgroundJobNameAttribute.GetName<TArgs>();
-        var jobId = await EnqueueAsync(jobName, args, priority, delay);
+        var jobId = await EnqueueAsync(jobName, args!, priority, delay);
         return jobId.ToString();
     }
 
diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/InMemoryBackgroundJobStore.cs b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/InMemoryBackgroundJobStore.cs
index 726d65d513..7abbc188ce 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/InMemoryBackgroundJobStore.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/InMemoryBackgroundJobStore.cs
@@ -25,7 +25,7 @@ public class InMemoryBackgroundJobStore : IBackgroundJobStore, ISingletonDepende
 
     public virtual Task<BackgroundJobInfo> FindAsync(Guid jobId)
     {
-        return Task.FromResult(_jobs.GetOrDefault(jobId));
+        return Task.FromResult(_jobs.GetOrDefault(jobId))!;
     }
 
     public virtual Task InsertAsync(BackgroundJobInfo jobInfo)