--- GNUmakefile.orig	2025-10-20 13:35:06 UTC
+++ GNUmakefile
@@ -17,8 +17,7 @@
 # Required version of Mailutils: major and minor numbers.  If patchlevel is
 # needed, set the VPAT variable.
 VMAJ = 3
-VMIN = 20
-VPAT = 92
+VMIN = 21
 
 # Installation prefix
 PREFIX = /usr/local
@@ -49,7 +48,7 @@ ifneq (,$(wildcard config.mk))
 endif
 
 ifeq ($(DEVMAILUTILS),)
-  CFLAGS  = $(O) $(shell mailutils cflags)
+  CFLAGS += $(O) $(shell mailutils cflags)
   LDFLAGS = $(shell mailutils ldflags all sieve)
   MU_INFO = mailutils info
 else
@@ -125,11 +124,11 @@ install: install-bin install-man
 
 install-bin: mbar 
 	$(MKHIER) $(DESTDIR)$(BINDIR)
-	$(INSTALL) mbar $(DESTDIR)$(BINDIR)
+	$(BSD_INSTALL_PROGRAM) mbar $(DESTDIR)$(BINDIR)
 
 install-man:
 	$(MKHIER) $(DESTDIR)$(MAN1DIR)
-	$(INSTALL) mbar.1 $(DESTDIR)$(MAN1DIR)
+	$(BSD_INSTALL_MAN) mbar.1 $(DESTDIR)$(MAN1DIR)
 
 # ###################
 # Distribution rules