diff -up mutt-1.10.0/configure.ac.nodotlock mutt-1.10.0/configure.ac
--- mutt-1.10.0/configure.ac.nodotlock	2018-05-14 23:51:53.000000000 +0200
+++ mutt-1.10.0/configure.ac	2018-05-23 15:09:21.186613968 +0200
@@ -528,9 +528,7 @@ int main (int argc, char **argv)
 }]])],[mutt_cv_worldwrite=yes],[mutt_cv_worldwrite=no],[mutt_cv_worldwrite=no])])
 
         mutt_cv_setgid=no
-        if test $mutt_cv_worldwrite = yes; then
-                AC_DEFINE(USE_DOTLOCK,1,[ Define to use dotlocking for mailboxes. ])
-        else
+        if test $mutt_cv_worldwrite != yes; then
 
                 AC_CACHE_CHECK(if $mutt_cv_mailpath is group writable, mutt_cv_groupwrite, [AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <sys/types.h>
 #include <sys/stat.h>
@@ -546,7 +544,6 @@ int main (int argc, char **argv)
 }]])],[mutt_cv_groupwrite=yes],[mutt_cv_groupwrite=no],[mutt_cv_groupwrite=no])])
 
                 if test $mutt_cv_groupwrite = yes; then
-                        AC_DEFINE(USE_DOTLOCK,1,[ Define to use dotlocking for mailboxes. ])
                         AC_DEFINE(USE_SETGID,1,[ Define if mutt should run setgid "mail". ])
                         mutt_cv_setgid=yes
                 fi
diff -up mutt-1.10.0/Makefile.am.nodotlock mutt-1.10.0/Makefile.am
--- mutt-1.10.0/Makefile.am.nodotlock	2018-05-23 15:11:05.477977659 +0200
+++ mutt-1.10.0/Makefile.am	2018-05-23 15:11:20.252170843 +0200
@@ -154,17 +154,6 @@ hcversion.h: $(srcdir)/mutt.h $(srcdir)/
 patchlist.c: $(srcdir)/PATCHES $(srcdir)/patchlist.sh
 	$(srcdir)/patchlist.sh < $(srcdir)/PATCHES > patchlist.c
 
-install-exec-hook:
-	if test -f $(DESTDIR)$(bindir)/mutt.dotlock && test -f $(DESTDIR)$(bindir)/mutt_dotlock ; then	\
-		rm -f $(DESTDIR)$(bindir)/mutt.dotlock ;		\
-		ln -sf $(DESTDIR)$(bindir)/mutt_dotlock $(DESTDIR)$(bindir)/mutt.dotlock ; \
-	fi
-	if test -f $(DESTDIR)$(bindir)/mutt_dotlock && test x$(DOTLOCK_GROUP) != x ; then \
-		chgrp $(DOTLOCK_GROUP) $(DESTDIR)$(bindir)/mutt_dotlock && \
-		chmod $(DOTLOCK_PERMISSION) $(DESTDIR)$(bindir)/mutt_dotlock || \
-		{ echo "Can't fix mutt_dotlock's permissions!  This is required to lock mailboxes in the mail spool directory." >&2 ; exit 1 ; } \
-	fi
-
 install-data-local:
 	$(MKDIR_P) $(DESTDIR)$(sysconfdir)
 	$(INSTALL) -m 644 $(srcdir)/mime.types $(DESTDIR)$(sysconfdir)/mime.types.dist