diff --git a/ICSharpCode.Decompiler.Tests/CorrectnessTestRunner.cs b/ICSharpCode.Decompiler.Tests/CorrectnessTestRunner.cs
index 499cc16d5..443485a81 100644
--- a/ICSharpCode.Decompiler.Tests/CorrectnessTestRunner.cs
+++ b/ICSharpCode.Decompiler.Tests/CorrectnessTestRunner.cs
@@ -443,9 +443,7 @@ namespace ICSharpCode.Decompiler.Tests
 				decompiledOutputFile = await Tester.CompileCSharp(decompiledCodeFile, options).ConfigureAwait(false);
 
 				await Tester.RunAndCompareOutput(testFileName, outputFile.PathToAssembly, decompiledOutputFile.PathToAssembly, decompiledCodeFile, (options & CompilerOptions.UseTestRunner) != 0, (options & CompilerOptions.Force32Bit) != 0);
-
 				Tester.RepeatOnIOError(() => File.Delete(decompiledCodeFile));
-				Tester.RepeatOnIOError(() => File.Delete(decompiledOutputFile.PathToAssembly));
 			}
 			finally
 			{
@@ -473,9 +471,7 @@ namespace ICSharpCode.Decompiler.Tests
 				decompiledOutputFile = await Tester.CompileCSharp(decompiledCodeFile, options).ConfigureAwait(false);
 
 				await Tester.RunAndCompareOutput(testFileName, outputFile.PathToAssembly, decompiledOutputFile.PathToAssembly, decompiledCodeFile, (options & CompilerOptions.UseTestRunner) != 0, (options & CompilerOptions.Force32Bit) != 0);
-
 				Tester.RepeatOnIOError(() => File.Delete(decompiledCodeFile));
-				Tester.RepeatOnIOError(() => File.Delete(decompiledOutputFile.PathToAssembly));
 			}
 			finally
 			{
@@ -499,9 +495,7 @@ namespace ICSharpCode.Decompiler.Tests
 				decompiledOutputFile = await Tester.CompileCSharp(decompiledCodeFile, options).ConfigureAwait(false);
 
 				await Tester.RunAndCompareOutput(testFileName, outputFile, decompiledOutputFile.PathToAssembly, decompiledCodeFile, (options & CompilerOptions.UseTestRunner) != 0, (options & CompilerOptions.Force32Bit) != 0).ConfigureAwait(false);
-
 				Tester.RepeatOnIOError(() => File.Delete(decompiledCodeFile));
-				Tester.RepeatOnIOError(() => File.Delete(decompiledOutputFile.PathToAssembly));
 			}
 			finally
 			{
diff --git a/ICSharpCode.Decompiler.Tests/Helpers/Tester.VB.cs b/ICSharpCode.Decompiler.Tests/Helpers/Tester.VB.cs
index 5ce1bf96b..d871bed94 100644
--- a/ICSharpCode.Decompiler.Tests/Helpers/Tester.VB.cs
+++ b/ICSharpCode.Decompiler.Tests/Helpers/Tester.VB.cs
@@ -47,7 +47,7 @@ namespace ICSharpCode.Decompiler.Tests.Helpers
 			if ((flags & CompilerOptions.UseMcsMask) == 0)
 			{
 				CompilerResults results = new CompilerResults();
-				results.PathToAssembly = outputFileName ?? Path.GetTempFileName();
+				results.PathToAssembly = outputFileName;
 
 				var (roslynVersion, languageVersion) = (flags & CompilerOptions.UseRoslynMask) switch {
 					0 => ("legacy", "11"),
diff --git a/ICSharpCode.Decompiler.Tests/Helpers/Tester.cs b/ICSharpCode.Decompiler.Tests/Helpers/Tester.cs
index c2ecd3f70..5a55e10c2 100644
--- a/ICSharpCode.Decompiler.Tests/Helpers/Tester.cs
+++ b/ICSharpCode.Decompiler.Tests/Helpers/Tester.cs
@@ -18,6 +18,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Reflection.PortableExecutable;
@@ -296,6 +297,7 @@ namespace ICSharpCode.Decompiler.Tests.Helpers
 
 		static string GetTargetFrameworkAttributeSnippetFile()
 		{
+			// Note: this leaks a temporary file, we're not attempting to delete it, because it is only one.
 			var tempFile = Path.GetTempFileName();
 			File.WriteAllText(tempFile, targetFrameworkAttributeSnippet);
 			return tempFile;
@@ -395,7 +397,7 @@ namespace ICSharpCode.Decompiler.Tests.Helpers
 			if ((flags & CompilerOptions.UseMcsMask) == 0)
 			{
 				CompilerResults results = new CompilerResults();
-				results.PathToAssembly = outputFileName ?? Path.GetTempFileName();
+				results.PathToAssembly = outputFileName;
 
 				var (roslynVersion, languageVersion) = (flags & CompilerOptions.UseRoslynMask) switch {
 					0 => ("legacy", "5"),
@@ -488,7 +490,7 @@ namespace ICSharpCode.Decompiler.Tests.Helpers
 			else
 			{
 				CompilerResults results = new CompilerResults();
-				results.PathToAssembly = outputFileName ?? Path.GetTempFileName();
+				results.PathToAssembly = outputFileName;
 				string testBasePath = RoundtripAssembly.TestDir;
 				if (!Directory.Exists(testBasePath))
 				{
@@ -828,11 +830,42 @@ namespace ICSharpCode.Decompiler.Tests.Helpers
 
 	public class CompilerResults
 	{
-		public string PathToAssembly { get; set; }
+		readonly HashSet<string> tempFiles = new(Decompiler.Util.Platform.FileNameComparer);
+		string pathToAssembly;
+
+		public string PathToAssembly {
+			get {
+				if (pathToAssembly == null)
+				{
+					pathToAssembly = Path.GetTempFileName();
+					tempFiles.Add(pathToAssembly);
+				}
+				return pathToAssembly;
+			}
+			set {
+				if (pathToAssembly != null)
+				{
+					throw new InvalidOperationException("PathToAssembly can only be set once");
+				}
+				pathToAssembly = value;
+			}
+		}
 
 		public void DeleteTempFiles()
 		{
+			foreach (var file in tempFiles)
+			{
+				Tester.RepeatOnIOError(() => File.Delete(file));
+			}
+		}
 
+		public void AddTempFile(string file)
+		{
+			if (!Path.IsPathFullyQualified(file))
+			{
+				throw new InvalidOperationException("file must be a fully qualified path");
+			}
+			tempFiles.Add(file);
 		}
 	}
 }
diff --git a/ICSharpCode.Decompiler.Tests/ILPrettyTestRunner.cs b/ICSharpCode.Decompiler.Tests/ILPrettyTestRunner.cs
index 2cf64cf18..237bdd402 100644
--- a/ICSharpCode.Decompiler.Tests/ILPrettyTestRunner.cs
+++ b/ICSharpCode.Decompiler.Tests/ILPrettyTestRunner.cs
@@ -278,6 +278,7 @@ namespace ICSharpCode.Decompiler.Tests
 			var decompiled = await Tester.DecompileCSharp(executable, settings).ConfigureAwait(false);
 
 			CodeAssert.FilesAreEqual(csFile, decompiled);
+			Tester.RepeatOnIOError(() => File.Delete(decompiled));
 		}
 
 		static readonly object copyLock = new object();
diff --git a/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs b/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs
index bc5b895f8..b2542be8d 100644
--- a/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs
+++ b/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs
@@ -745,6 +745,7 @@ namespace ICSharpCode.Decompiler.Tests
 
 			// 3. Compile
 			CodeAssert.FilesAreEqual(csFile, decompiled, Tester.GetPreprocessorSymbols(cscOptions).ToArray());
+			Tester.RepeatOnIOError(() => File.Delete(decompiled));
 		}
 	}
 }
diff --git a/ICSharpCode.Decompiler.Tests/UglyTestRunner.cs b/ICSharpCode.Decompiler.Tests/UglyTestRunner.cs
index f33eb21ca..1e2cceb6c 100644
--- a/ICSharpCode.Decompiler.Tests/UglyTestRunner.cs
+++ b/ICSharpCode.Decompiler.Tests/UglyTestRunner.cs
@@ -163,6 +163,7 @@ namespace ICSharpCode.Decompiler.Tests
 			var decompiled = await Tester.DecompileCSharp(executable, decompilerSettings).ConfigureAwait(false);
 
 			CodeAssert.FilesAreEqual(expectedFile, decompiled, Tester.GetPreprocessorSymbols(cscOptions).ToArray());
+			Tester.RepeatOnIOError(() => File.Delete(decompiled));
 		}
 	}
 }
diff --git a/ICSharpCode.Decompiler.Tests/VBPrettyTestRunner.cs b/ICSharpCode.Decompiler.Tests/VBPrettyTestRunner.cs
index 06952a8c5..b5db5269b 100644
--- a/ICSharpCode.Decompiler.Tests/VBPrettyTestRunner.cs
+++ b/ICSharpCode.Decompiler.Tests/VBPrettyTestRunner.cs
@@ -139,6 +139,7 @@ namespace ICSharpCode.Decompiler.Tests
 			var decompiled = await Tester.DecompileCSharp(executable.PathToAssembly, settings).ConfigureAwait(false);
 
 			CodeAssert.FilesAreEqual(csFile, decompiled, Tester.GetPreprocessorSymbols(options).ToArray());
+			Tester.RepeatOnIOError(() => File.Delete(decompiled));
 		}
 	}
 }