diff --git a/README.md b/README.md
index 7f9609b..66d8dee 100644
--- a/README.md
+++ b/README.md
@@ -82,7 +82,7 @@ and even use a parameter from another field not annotated with `AutoConstructorI
 
 ### Get-only properties
 
-Since version 3.0.0, get-only properties (`public int Property { get; }`) are injected by the generator by default.
+Get-only properties (`public int Property { get; }`) are injected by the generator by default.
 The behavior of the injection can be modified using [auto-implemented property field-targeted attributes](https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/csharp-7.3/auto-prop-field-attrs) on its backing field. The following code show an injected get-only property with a custom injecter:
 
 ```csharp
@@ -96,11 +96,11 @@ public int Property { get; }
 
 ### Generating `ArgumentNullException`
 
-By default, null checks with `ArgumentNullException` will be generated when needed.
-To disable this behavior, set `AutoConstructor_DisableNullChecking` to `false` in the project file:
+By default, null checks with `ArgumentNullException` are not generated when needed.
+To enable this behavior, set `AutoConstructor_DisableNullChecking` to `false` in the project file:
 
 ``` xml
-<AutoConstructor_DisableNullChecking>true</AutoConstructor_DisableNullChecking>
+<AutoConstructor_DisableNullChecking>false</AutoConstructor_DisableNullChecking>
 ```
 
 ### Generating XML documentation comment
diff --git a/src/AutoConstructor.Generator/AutoConstructorGenerator.cs b/src/AutoConstructor.Generator/AutoConstructorGenerator.cs
index 219db23..3ebc581 100644
--- a/src/AutoConstructor.Generator/AutoConstructorGenerator.cs
+++ b/src/AutoConstructor.Generator/AutoConstructorGenerator.cs
@@ -93,7 +93,7 @@ private static void Execute(Compilation compilation, ImmutableArray<ClassDeclara
                     filename = $"{symbol.ContainingNamespace.ToDisplayString()}.{filename}";
                 }
 
-                bool emitNullChecks = true;
+                bool emitNullChecks = false;
                 if (options.TryGetValue("build_property.AutoConstructor_DisableNullChecking", out string? disableNullCheckingSwitch))
                 {
                     emitNullChecks = !disableNullCheckingSwitch.Equals("true", StringComparison.OrdinalIgnoreCase);
diff --git a/tests/AutoConstructor.Tests/GeneratorTests.cs b/tests/AutoConstructor.Tests/GeneratorTests.cs
index 77b75c7..7464ba7 100644
--- a/tests/AutoConstructor.Tests/GeneratorTests.cs
+++ b/tests/AutoConstructor.Tests/GeneratorTests.cs
@@ -318,12 +318,7 @@ public Test(string t)
 }}
 ";
 
-        (string, SourceText) configFile = ("/.editorconfig", SourceText.From($@"
-is_global=true
-build_property.AutoConstructor_DisableNullChecking = {disableNullChecks}
-"));
-
-        await VerifySourceGenerator.RunAsync(code, generated, configFiles: new[] { configFile });
+        await VerifySourceGenerator.RunAsync(code, generated, configFileContent: $"build_property.AutoConstructor_DisableNullChecking = {disableNullChecks}");
     }
 
     [Theory]
@@ -379,12 +374,10 @@ public Test(string t1, string t2)
 ";
         }
 
-        (string, SourceText) configFile = ("/.editorconfig", SourceText.From($@"
-is_global=true
-build_property.AutoConstructor_GenerateConstructorDocumentation = {generateDocumentation}
-"));
-
-        await VerifySourceGenerator.RunAsync(code, generated, configFiles: new[] { configFile });
+        await VerifySourceGenerator.RunAsync(
+            code,
+            generated,
+            configFileContent: $"build_property.AutoConstructor_GenerateConstructorDocumentation = {generateDocumentation}");
     }
 
     [Theory]
@@ -430,23 +423,19 @@ public Test(string t1, string t2)
 }}
 ";
 
-        var configSource = SourceText.From(@"
-is_global=true
+        string configFileContent = @"
 build_property.AutoConstructor_GenerateConstructorDocumentation = true
-");
+";
 
         if (hasCustomComment)
         {
-            configSource = SourceText.From($@"
-is_global=true
+            configFileContent = $@"
 build_property.AutoConstructor_GenerateConstructorDocumentation = true
 build_property.AutoConstructor_ConstructorDocumentationComment = {commentConfig}
-");
+";
         }
 
-        (string, SourceText) configFile = ("/.editorconfig", configSource);
-
-        await VerifySourceGenerator.RunAsync(code, generated, configFiles: new[] { configFile });
+        await VerifySourceGenerator.RunAsync(code, generated, configFileContent: configFileContent);
     }
 
     [Fact]
@@ -786,12 +775,8 @@ public Test(int injected, int injectedWithDocumentation, int alsoInjectedEvenWhe
     }
 }
 ";
-        (string, SourceText) configFile = ("/.editorconfig", SourceText.From(@"
-is_global=true
-build_property.AutoConstructor_GenerateConstructorDocumentation = true
-"));
 
-        await VerifySourceGenerator.RunAsync(code, generated, configFiles: new[] { configFile });
+        await VerifySourceGenerator.RunAsync(code, generated, configFileContent: "build_property.AutoConstructor_GenerateConstructorDocumentation = true");
     }
 
     [Fact]
diff --git a/tests/AutoConstructor.Tests/Verifiers/CSharpSourceGeneratorVerifier`1.cs b/tests/AutoConstructor.Tests/Verifiers/CSharpSourceGeneratorVerifier`1.cs
index abd9a1e..d0b81f2 100644
--- a/tests/AutoConstructor.Tests/Verifiers/CSharpSourceGeneratorVerifier`1.cs
+++ b/tests/AutoConstructor.Tests/Verifiers/CSharpSourceGeneratorVerifier`1.cs
@@ -18,7 +18,7 @@ public static async Task RunAsync(
         string? generatedName = "Test.Test.g.cs",
         bool nullable = false,
         IEnumerable<DiagnosticResult>? diagnostics = null,
-        IEnumerable<(string filename, SourceText content)>? configFiles = null)
+        string? configFileContent = null)
     {
         var test = new CSharpSourceGeneratorVerifier<TSourceGenerator>.Test()
         {
@@ -55,10 +55,11 @@ public static async Task RunAsync(
             test.TestState.ExpectedDiagnostics.AddRange(diagnostics);
         }
 
-        if (configFiles is not null)
-        {
-            test.TestState.AnalyzerConfigFiles.AddRange(configFiles);
-        }
+        // Enable null checks for the tests.
+        test.TestState.AnalyzerConfigFiles.Add(("/.editorconfig", SourceText.From($@"
+is_global=true
+build_property.AutoConstructor_DisableNullChecking = false
+{configFileContent}")));
 
         await test.RunAsync();
     }