-diff -urN exim-4.60.org/OS/Makefile-Linux exim-4.60/OS/Makefile-Linux
---- exim-4.60.org/OS/Makefile-Linux 2005-11-28 11:57:32.000000000 +0100
-+++ exim-4.60/OS/Makefile-Linux 2006-02-17 20:17:00.698452750 +0100
-@@ -9,7 +9,7 @@
- CHOWN_COMMAND=look_for_it
- CHGRP_COMMAND=look_for_it
-
--CFLAGS=-O -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
-+CFLAGS=-D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE $(CUSTOM_CFLAGS)
+--- exim-4.94.org/OS/Makefile-Linux 2020-05-30 22:35:38.000000000 +0200
++++ exim-4.94/OS/Makefile-Linux 2020-11-27 08:08:51.397823884 +0100
+@@ -16,7 +16,7 @@ CHMOD_COMMAND=look_for_it
+ # The system cc may be gcc or clang; do not force gcc
+ CC=cc
+ # Preserve CFLAGS and CFLAGS_DYNAMIC from the caller/environment
+-CFLAGS ?= -O -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
++CFLAGS ?= -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE $(CUSTOM_CFLAGS)
+ CFLAGS_DYNAMIC ?= -shared -rdynamic
DBMLIB = -ldb
- USE_DB = yes