diff --git a/libexec/mail.local/Makefile b/libexec/mail.local/Makefile
index ea539a67d348..10371e436017 100644
--- a/libexec/mail.local/Makefile
+++ b/libexec/mail.local/Makefile
@@ -2,7 +2,9 @@
 
 PROG=	mail.local
 MAN8=	mail.local.8
-# CFLAGS+= -DEXTRA_SAFETY
+.if defined(DONT_FSYNC)
+CFLAGS+= -DDONT_FSYNC
+.endif
 BINOWN=	root
 BINMODE=4555
 INSTALLFLAGS=-fschg
diff --git a/libexec/mail.local/mail.local.c b/libexec/mail.local/mail.local.c
index d7b43a607f34..0d80972814dc 100644
--- a/libexec/mail.local/mail.local.c
+++ b/libexec/mail.local/mail.local.c
@@ -298,7 +298,7 @@ err1:		(void)close(mbfd);
 		return;
 	}
 
-#ifdef EXTRA_SAFETY
+#ifndef DONT_FSYNC
 	/* Flush to disk, don't wait for update. */
 	if (fsync(mbfd)) {
 		e_to_sys(errno);