diff --git a/Tests/LinqToDB.EntityFrameworkCore.BaseTests/LinqToDB.EntityFrameworkCore.BaseTests.csproj b/Tests/LinqToDB.EntityFrameworkCore.BaseTests/LinqToDB.EntityFrameworkCore.BaseTests.csproj
index 002be19..bf604a6 100644
--- a/Tests/LinqToDB.EntityFrameworkCore.BaseTests/LinqToDB.EntityFrameworkCore.BaseTests.csproj
+++ b/Tests/LinqToDB.EntityFrameworkCore.BaseTests/LinqToDB.EntityFrameworkCore.BaseTests.csproj
@@ -10,6 +10,7 @@
 
 	<ItemGroup>
 		<PackageReference Include="linq2db.Tools" Version="3.2.3" />
+		<PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="5.0.0" />
 		<PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="3.1.11" />
 		<PackageReference Include="Microsoft.Extensions.Logging" Version="3.1.11" />
 		<PackageReference Include="Microsoft.Extensions.Logging.Console" Version="3.1.11" />
diff --git a/Tests/LinqToDB.EntityFrameworkCore.BaseTests/Logging/TestLogger.cs b/Tests/LinqToDB.EntityFrameworkCore.BaseTests/Logging/TestLogger.cs
index 6879d86..d637fbc 100644
--- a/Tests/LinqToDB.EntityFrameworkCore.BaseTests/Logging/TestLogger.cs
+++ b/Tests/LinqToDB.EntityFrameworkCore.BaseTests/Logging/TestLogger.cs
@@ -13,7 +13,9 @@ internal class TestLogger : ILogger
 		private static readonly string _newLineWithMessagePadding;
 
 		// ConsoleColor does not have a value to specify the 'Default' color
+#pragma warning disable 649
 		private readonly ConsoleColor? DefaultConsoleColor;
+#pragma warning restore 649
 
 		private readonly string _name;
 
diff --git a/Tests/LinqToDB.EntityFrameworkCore.PostgreSQL.Tests/NpgSqlTests.cs b/Tests/LinqToDB.EntityFrameworkCore.PostgreSQL.Tests/NpgSqlTests.cs
index 18e885d..ef7d1ef 100644
--- a/Tests/LinqToDB.EntityFrameworkCore.PostgreSQL.Tests/NpgSqlTests.cs
+++ b/Tests/LinqToDB.EntityFrameworkCore.PostgreSQL.Tests/NpgSqlTests.cs
@@ -31,11 +31,13 @@ public NpgSqlTests()
 			_options = optionsBuilder.Options;
 		}
 
-		private NpgSqlEnititesContext CreateNpgSqlExntitiesContext()
+		private NpgSqlEnititesContext CreateNpgSqlEntitiesContext()
 		{
 			var ctx = new NpgSqlEnititesContext(_options);
 			ctx.Database.EnsureDeleted();
 			ctx.Database.EnsureCreated();
+			ctx.Database.ExecuteSqlRaw("create schema \"views\"");
+			ctx.Database.ExecuteSqlRaw("create view \"views\".\"EventsView\" as select \"Name\" from \"Events\"");
 			return ctx;
 		}
 
@@ -43,7 +45,7 @@ private NpgSqlEnititesContext CreateNpgSqlExntitiesContext()
 		[Test]
 		public void TestFunctionsMapping()
 		{
-			using (var db = CreateNpgSqlExntitiesContext())
+			using (var db = CreateNpgSqlEntitiesContext())
 			{
 				var date = DateTime.UtcNow;
 
diff --git a/Tests/LinqToDB.EntityFrameworkCore.PostgreSQL.Tests/SampleTests/AAA.cs b/Tests/LinqToDB.EntityFrameworkCore.PostgreSQL.Tests/SampleTests/AAA.cs
index 475ffce..756370e 100644
--- a/Tests/LinqToDB.EntityFrameworkCore.PostgreSQL.Tests/SampleTests/AAA.cs
+++ b/Tests/LinqToDB.EntityFrameworkCore.PostgreSQL.Tests/SampleTests/AAA.cs
@@ -1,6 +1,9 @@
 using System;
 using System.Threading.Tasks;
 
+#pragma warning disable 8604
+#pragma warning disable CS8625
+
 namespace LinqToDB.EntityFrameworkCore.PostgreSQL.Tests.SampleTests
 {
 	public class Unit
diff --git a/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/IssueTests.cs b/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/IssueTests.cs
index 2afa3d8..27c0815 100644
--- a/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/IssueTests.cs
+++ b/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/IssueTests.cs
@@ -9,7 +9,7 @@ namespace LinqToDB.EntityFrameworkCore.SqlServer.Tests
 	[TestFixture]
 	public class IssueTests : TestsBase
 	{
-		private DbContextOptions<IssueContext>? _options;
+		private DbContextOptions<IssueContext> _options = null!;
 		private bool _created;
 
 		public IssueTests()
diff --git a/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/Models/IssueModel/IssueContext.cs b/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/Models/IssueModel/IssueContext.cs
index 76d8d99..e8dee5c 100644
--- a/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/Models/IssueModel/IssueContext.cs
+++ b/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/Models/IssueModel/IssueContext.cs
@@ -43,7 +43,7 @@ protected override void OnModelCreating(ModelBuilder modelBuilder)
 			modelBuilder
 				.Entity<Patent>()
 				.HasOne(p => p.Assessment)
-				.WithOne(pa => pa.Patent)
+				.WithOne(pa => pa!.Patent)
 				.HasForeignKey<PatentAssessment>(pa => pa.PatentId)
 				.OnDelete(DeleteBehavior.Restrict);
 
diff --git a/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/ToolsTests.cs b/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/ToolsTests.cs
index 6e55836..d50e25b 100644
--- a/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/ToolsTests.cs
+++ b/Tests/LinqToDB.EntityFrameworkCore.SqlServer.Tests/ToolsTests.cs
@@ -669,7 +669,7 @@ public async Task TestSetUpdate([Values(true, false)] bool enableFilter)
 		{
 			using (var ctx = CreateContext(enableFilter))
 			{
-				var customer = await ctx.Customers.FirstOrDefaultAsync();
+				var customer = await ctx.Customers.FirstAsync();
 
 				var updatable = ctx.Customers.Where(c => c.CustomerId == customer.CustomerId)
 					.Set(c => c.CompanyName, customer.CompanyName);