diff --git a/src/IbanNet/Validation/Rules/QrIbanRule.cs b/src/IbanNet/Validation/Rules/QrIbanRule.cs
index 9db8baf..bc15055 100644
--- a/src/IbanNet/Validation/Rules/QrIbanRule.cs
+++ b/src/IbanNet/Validation/Rules/QrIbanRule.cs
@@ -12,6 +12,11 @@ public sealed class QrIbanRule : IIbanValidationRule
     /// <inheritdoc />
     public ValidationRuleResult Validate(ValidationRuleContext context)
     {
+        if (context is null)
+        {
+            throw new ArgumentNullException(nameof(context));
+        }
+
         IbanCountry? country = context.Country;
         if (country != null && IsValid(country, context.Value.Substring(country.Bank.Position, country.Bank.Length)))
         {
@@ -24,7 +29,7 @@ public ValidationRuleResult Validate(ValidationRuleContext context)
     internal static bool IsValid(IbanCountry country, string iidStr)
     {
         return country.TwoLetterISORegionName is "CH" or "LI"
-           && int.TryParse(iidStr, NumberStyles.None, NumberFormatInfo.InvariantInfo, out int iid)
-           && iid is >= 30000 and <= 31999;
+         && int.TryParse(iidStr, NumberStyles.None, NumberFormatInfo.InvariantInfo, out int iid)
+         && iid is >= 30000 and <= 31999;
     }
 }
diff --git a/test/IbanNet.Tests/Validation/Rules/IsValidQrIbanRuleTests.cs b/test/IbanNet.Tests/Validation/Rules/IsValidQrIbanRuleTests.cs
index 8fb97be..db7287b 100644
--- a/test/IbanNet.Tests/Validation/Rules/IsValidQrIbanRuleTests.cs
+++ b/test/IbanNet.Tests/Validation/Rules/IsValidQrIbanRuleTests.cs
@@ -1,9 +1,9 @@
-using IbanNet.Validation.Results;
-using IbanNet.Registry;
+using IbanNet.Registry;
+using IbanNet.Validation.Results;
 
 namespace IbanNet.Validation.Rules;
 
-public class IsValidQrIbanRuleTests
+public sealed class IsValidQrIbanRuleTests
 {
     private readonly QrIbanRule _sut;
 
@@ -25,8 +25,12 @@ public IsValidQrIbanRuleTests()
     [Theory]
     public void Given_invalid_values_it_should_return_success(string iban)
     {
-        ValidationRuleResult actual = _sut.Validate(new ValidationRuleContext(iban, IbanRegistry.Default[iban.Substring(0, 2)]));
+        IbanCountry country = IbanRegistry.Default[iban.Substring(0, 2)];
 
+        // Act
+        ValidationRuleResult actual = _sut.Validate(new ValidationRuleContext(iban, country));
+
+        // Assert
         actual.Should().BeOfType<InvalidQrIbanResult>();
     }
 
@@ -35,8 +39,26 @@ public void Given_invalid_values_it_should_return_success(string iban)
     [Theory]
     public void Given_valid_values_it_should_return_success(string iban)
     {
-        ValidationRuleResult actual = _sut.Validate(new ValidationRuleContext(iban, IbanRegistry.Default[iban.Substring(0, 2)]));
+        IbanCountry country = IbanRegistry.Default[iban.Substring(0, 2)];
+
+        // Act
+        ValidationRuleResult actual = _sut.Validate(new ValidationRuleContext(iban, country));
 
+        // Assert
         actual.Should().Be(ValidationRuleResult.Success);
     }
+
+    [Fact]
+    public void Given_that_context_is_null_when_validating_it_should_throw()
+    {
+        ValidationRuleContext? context = null;
+
+        // Act
+        Action act = () => _sut.Validate(context!);
+
+        // Assert
+        act.Should()
+            .Throw<ArgumentNullException>()
+            .WithParameterName(nameof(context));
+    }
 }