diff --git a/developers/fundamentals/QubesArchitecture.md b/developers/fundamentals/QubesArchitecture.md
index 7fda909d..54febfcd 100644
--- a/developers/fundamentals/QubesArchitecture.md
+++ b/developers/fundamentals/QubesArchitecture.md
@@ -29,3 +29,4 @@ Key Architecture features
 -   Qubes GUI provides isolation between apps sharing the same desktop
 -   Secure system boot based (optional)
 
+[Architecture Spec v0.3 [PDF]](/attachment/wiki/QubesArchitecture/arch-spec-0.3.pdf) (The original 2009 document that started this all...)