diff --git a/src/DiffEngine/DiffRunner.cs b/src/DiffEngine/DiffRunner.cs
index c48db96f64..9b755b9a62 100644
--- a/src/DiffEngine/DiffRunner.cs
+++ b/src/DiffEngine/DiffRunner.cs
@@ -43,7 +43,7 @@ public static void Kill(string tempFile, string targetFile)
 
         public static LaunchResult Launch(DiffTool tool, string tempFile, string targetFile)
         {
-            Guard.AgainstNullOrEmpty(tempFile, nameof(tempFile));
+            Guard.FileExists(tempFile, nameof(tempFile));
             Guard.AgainstNullOrEmpty(targetFile, nameof(targetFile));
             var extension = Extensions.GetExtension(tempFile);
             if (!DiffTools.TryFind(tool, extension, out var resolvedTool))
@@ -59,7 +59,7 @@ public static LaunchResult Launch(DiffTool tool, string tempFile, string targetF
         /// </summary>
         public static LaunchResult Launch(string tempFile, string targetFile)
         {
-            Guard.AgainstNullOrEmpty(tempFile, nameof(tempFile));
+            Guard.FileExists(tempFile, nameof(tempFile));
             Guard.AgainstNullOrEmpty(targetFile, nameof(targetFile));
             var extension = Extensions.GetExtension(tempFile);
 
@@ -77,14 +77,6 @@ static LaunchResult Launch(ResolvedDiffTool diffTool, string tempFile, string ta
             {
                 return LaunchResult.TooManyRunningDiffTools;
             }
-            //TODO: throw if both dont exist
-            if (!File.Exists(tempFile))
-            {
-                if (!AllFiles.TryCreateFile(tempFile, true))
-                {
-                    return LaunchResult.NoEmptyFileForExtension;
-                }
-            }
 
             if (!File.Exists(targetFile))
             {