diff --git a/OpenTK.sln b/OpenTK.sln
index 9ab581b5..dc1d2a23 100644
--- a/OpenTK.sln
+++ b/OpenTK.sln
@@ -1,5 +1,5 @@
 
-Microsoft Visual Studio Solution File, Format Version 12.00
+Microsoft Visual Studio Solution File, Format Version 11.00
 # Visual Studio 2012
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "OpenTK", "Source\OpenTK\OpenTK.csproj", "{A37A7E14-0000-0000-0000-000000000000}"
 	ProjectSection(ProjectDependencies) = postProject