From 0a0cdab35f9904d5bf12996adf0def056a1207a5 Mon Sep 17 00:00:00 2001
From: mmahoney <mmahoney@fb.com>
Date: Fri, 8 Jun 2018 17:05:27 -0400
Subject: [PATCH] RFC: Require Interfaces to implement 1+ Objects. Re-applies
 #424, but as an RFC. This change is a major spec breaking change, and if it
 is desireable, we should provide an upgrade path for existing schemas.

---
 spec/Section 3 -- Type System.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/spec/Section 3 -- Type System.md b/spec/Section 3 -- Type System.md
index 5c0c9561f..fae28e6d5 100644
--- a/spec/Section 3 -- Type System.md	
+++ b/spec/Section 3 -- Type System.md	
@@ -1013,6 +1013,7 @@ Interface types have the potential to be invalid if incorrectly defined.
    type; no two fields may share the same name.
 3. Each field of an Interface type must not have a name which begins with the
    characters {"__"} (two underscores).
+4. An Interface type must be implemented by at least one Object type.
 
 
 ### Interface Extensions