diff --git a/StanHeaders/inst/include/upstream b/StanHeaders/inst/include/upstream
index a582c8020..677398998 160000
--- a/StanHeaders/inst/include/upstream
+++ b/StanHeaders/inst/include/upstream
@@ -1 +1 @@
-Subproject commit a582c8020d7947b29414b3d74b28565702973111
+Subproject commit 677398998e7907c83d4cc8189a5ad4ade8cd2b34