diff --git a/Pipeline/Build.MutationTests.cs b/Pipeline/Build.MutationTests.cs
index a83cd765d..f646ff4d8 100644
--- a/Pipeline/Build.MutationTests.cs
+++ b/Pipeline/Build.MutationTests.cs
@@ -150,7 +150,6 @@ private void ExecuteMutationTest(Project project, Project[] testProjects)
 
 		DotNetToolInstall(_ => _
 			.SetPackageName("dotnet-stryker")
-			.SetVersion("4.7.0")
 			.SetToolInstallationPath(toolPath));
 
 		string branchName = BranchName;
diff --git a/Source/aweXpect.Core/Core/Nodes/AsyncMappingNode.cs b/Source/aweXpect.Core/Core/Nodes/AsyncMappingNode.cs
index b7d70a621..3029a5e46 100644
--- a/Source/aweXpect.Core/Core/Nodes/AsyncMappingNode.cs
+++ b/Source/aweXpect.Core/Core/Nodes/AsyncMappingNode.cs
@@ -43,16 +43,16 @@ public override async Task<ConstraintResult> IsMetBy<TValue>(
 			return result.Fail("it was <null>", value);
 		}
 
-		if (value is not TSource typedValue)
+		if (value is TSource typedValue)
 		{
-			throw new InvalidOperationException(
-					$"The member type for the actual value in the which node did not match.{Environment.NewLine}Expected: {Formatter.Format(typeof(TSource))},{Environment.NewLine}   Found: {Formatter.Format(value.GetType())}")
-				.LogTrace();
+			TTarget matchingValue = await _memberAccessor.AccessMember(typedValue);
+			ConstraintResult memberResult = await base.IsMetBy(matchingValue, context, cancellationToken);
+			return memberResult.UseValue(value);
 		}
 
-		TTarget matchingValue = await _memberAccessor.AccessMember(typedValue);
-		ConstraintResult memberResult = await base.IsMetBy(matchingValue, context, cancellationToken);
-		return memberResult.UseValue(value);
+		throw new InvalidOperationException(
+				$"The member type for the actual value in the which node did not match.{Environment.NewLine}Expected: {Formatter.Format(typeof(TSource))},{Environment.NewLine}   Found: {Formatter.Format(value.GetType())}")
+			.LogTrace();
 	}
 
 	/// <inheritdoc cref="object.Equals(object?)" />
diff --git a/Source/aweXpect.Core/Core/Nodes/MappingNode.cs b/Source/aweXpect.Core/Core/Nodes/MappingNode.cs
index 6f116b08d..9f0a5a578 100644
--- a/Source/aweXpect.Core/Core/Nodes/MappingNode.cs
+++ b/Source/aweXpect.Core/Core/Nodes/MappingNode.cs
@@ -43,16 +43,16 @@ public override async Task<ConstraintResult> IsMetBy<TValue>(
 			return result.Fail("it was <null>", value);
 		}
 
-		if (value is not TSource typedValue)
+		if (value is TSource typedValue)
 		{
-			throw new InvalidOperationException(
-					$"The member type for the actual value in the which node did not match.{Environment.NewLine}Expected: {Formatter.Format(typeof(TSource))},{Environment.NewLine}   Found: {Formatter.Format(value.GetType())}")
-				.LogTrace();
+			TTarget matchingValue = _memberAccessor.AccessMember(typedValue);
+			ConstraintResult memberResult = await base.IsMetBy(matchingValue, context, cancellationToken);
+			return memberResult.UseValue(value);
 		}
 
-		TTarget matchingValue = _memberAccessor.AccessMember(typedValue);
-		ConstraintResult memberResult = await base.IsMetBy(matchingValue, context, cancellationToken);
-		return memberResult.UseValue(value);
+		throw new InvalidOperationException(
+				$"The member type for the actual value in the which node did not match.{Environment.NewLine}Expected: {Formatter.Format(typeof(TSource))},{Environment.NewLine}   Found: {Formatter.Format(value.GetType())}")
+			.LogTrace();
 	}
 
 	/// <inheritdoc cref="object.Equals(object?)" />
diff --git a/Source/aweXpect.Core/Core/Nodes/WhichNode.cs b/Source/aweXpect.Core/Core/Nodes/WhichNode.cs
index 26fb345a9..5d14cac52 100644
--- a/Source/aweXpect.Core/Core/Nodes/WhichNode.cs
+++ b/Source/aweXpect.Core/Core/Nodes/WhichNode.cs
@@ -90,26 +90,26 @@ public override async Task<ConstraintResult> IsMetBy<TValue>(
 				FurtherProcessingStrategy.IgnoreResult, default);
 		}
 
-		if (value is not TSource typedValue)
+		if (value is TSource typedValue)
 		{
-			throw new InvalidOperationException(
-					$"The member type for the actual value in the which node did not match.{Environment.NewLine}     Found: {Formatter.Format(value.GetType())}{Environment.NewLine}  Expected: {Formatter.Format(typeof(TSource))}")
-				.LogTrace();
-		}
+			TMember? matchingValue;
+			if (_memberAccessor != null)
+			{
+				matchingValue = _memberAccessor(typedValue);
+			}
+			else
+			{
+				matchingValue = await _asyncMemberAccessor!.Invoke(typedValue);
+			}
 
-		TMember? matchingValue;
-		if (_memberAccessor != null)
-		{
-			matchingValue = _memberAccessor(typedValue);
-		}
-		else
-		{
-			matchingValue = await _asyncMemberAccessor!.Invoke(typedValue);
+			ConstraintResult result = await _inner.IsMetBy(matchingValue, context, cancellationToken);
+			return CombineResults(parentResult, result, _separator ?? "", FurtherProcessingStrategy.IgnoreResult,
+				matchingValue);
 		}
 
-		ConstraintResult result = await _inner.IsMetBy(matchingValue, context, cancellationToken);
-		return CombineResults(parentResult, result, _separator ?? "", FurtherProcessingStrategy.IgnoreResult,
-			matchingValue);
+		throw new InvalidOperationException(
+				$"The member type for the actual value in the which node did not match.{Environment.NewLine}     Found: {Formatter.Format(value.GetType())}{Environment.NewLine}  Expected: {Formatter.Format(typeof(TSource))}")
+			.LogTrace();
 	}
 
 	/// <inheritdoc cref="object.Equals(object?)" />