--- src/Makevars.orig	2023-05-12 20:31:07.000000000 +0800
+++ src/Makevars	2023-07-01 21:09:08.000000000 +0800
@@ -1,6 +1,5 @@
-# We no longer specify `CXX_STD = CXX11` since modern versions of R require
-# C++11 as a minimum. This also allows more modern compilers to use C++14, which
-# has constexpr benefits.
+# CXX11 is required. Using a newer standard breaks build on 10.7–10.11:
+# https://github.com/r-lib/tzdb/issues/34
 
 # -DINSTALL=dummy
 # To keep some problematic code from running on windows if INSTALL isn't defined.
@@ -26,6 +25,8 @@
 # Because of these issues, we instead default to using an uncompressed
 # text version of the database that we ship with tzdb.
 
+CXX_STD = CXX11
+
 PKG_CXXFLAGS = \
 	-I../inst/include \
 	-DINSTALL=dummy \