diff --git a/src/CamBooth/EDSDKLib/API/Base/CameraMock.cs b/src/CamBooth/EDSDKLib/API/Base/CameraMock.cs
index ef51f0d..8c06aa5 100644
--- a/src/CamBooth/EDSDKLib/API/Base/CameraMock.cs
+++ b/src/CamBooth/EDSDKLib/API/Base/CameraMock.cs
@@ -146,7 +146,7 @@ namespace EDSDKLib.API.Base
 		/// <exception cref="ArgumentNullException">The DownloadInfo is null</exception>
 		public void DownloadFile(IDownloadInfo Info, string directory)
 		{
-			File.WriteAllBytes(Path.Combine(directory, Info.FileName), File.ReadAllBytes(this.mockImageFiles[new Random().Next(1, 99)].FullName));
+			File.WriteAllBytes(Path.Combine(directory, Info.FileName), File.ReadAllBytes(this.mockImageFiles[new Random().Next(1, this.mockImageFiles.Count)].FullName));
 		}
 		
 		/// <summary>