From 3478579dce9895f5efea337c5599c3176bb74d73 Mon Sep 17 00:00:00 2001
From: Leonardo de Moura <leonardo@microsoft.com>
Date: Tue, 18 Aug 2020 18:16:36 -0700
Subject: [PATCH] chore: fix typo

---
 src/Lean/CoreM.lean | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Lean/CoreM.lean b/src/Lean/CoreM.lean
index 3936554d7e..6fe140231c 100644
--- a/src/Lean/CoreM.lean
+++ b/src/Lean/CoreM.lean
@@ -29,7 +29,7 @@ inductive Exception
 | kernel (ex : KernelException) (opts : Options)
 | error  (ref : Syntax) (msg : MessageData)
 
-abbrev ECoreM (ε : Type) := ReaderT Context $ StateT State $ EIO ε
+abbrev ECoreM (ε : Type) := ReaderT Context $ StateRefT State $ EIO ε
 
 abbrev CoreM := ECoreM Exception