diff -up mandoc-1.14.5/Makefile.orig mandoc-1.14.5/Makefile
--- mandoc-1.14.5/Makefile.orig	2019-10-16 10:12:02.427888365 -0400
+++ mandoc-1.14.5/Makefile	2019-10-16 10:12:39.502809508 -0400
@@ -446,7 +446,7 @@ lib-install: libmandoc.so.$(SOVERSION)
 	$(INSTALL_LIB) libmandoc.so.$(SOVERSION) $(DESTDIR)$(LIBDIR)
 	ln -s libmandoc.so.$(SOVERSION) $(DESTDIR)$(LIBDIR)/libmandoc.so.$(SOMAJOR)
 	ln -s libmandoc.so.$(SOVERSION) $(DESTDIR)$(LIBDIR)/libmandoc.so
-	$(INSTALL_LIB) eqn.h man.h mandoc.h mandoc_aux.h mandoc_parse.h \
+	$(INSTALL_HDR) eqn.h man.h mandoc.h mandoc_aux.h mandoc_parse.h \
 		mdoc.h roff.h tbl.h $(DESTDIR)$(INCLUDEDIR)
 	$(INSTALL_MAN) mandoc.3 mandoc_escape.3 mandoc_malloc.3 \
 		mansearch.3 mchars_alloc.3 tbl.3 $(DESTDIR)$(MANDIR)/man3
diff -up mandoc-1.14.5/configure.orig mandoc-1.14.5/configure
--- mandoc-1.14.5/configure.orig	2019-03-10 05:56:43.000000000 -0400
+++ mandoc-1.14.5/configure	2019-10-16 10:13:30.798700410 -0400
@@ -124,6 +124,7 @@ MANM_TBL="tbl"
 INSTALL="install"
 INSTALL_PROGRAM=
 INSTALL_LIB=
+INSTALL_HDR=
 INSTALL_MAN=
 INSTALL_DATA=
 LN="ln -f"
@@ -579,6 +580,7 @@ exec > Makefile.local
 
 [ -z "${INSTALL_PROGRAM}" ] && INSTALL_PROGRAM="${INSTALL} -m 0555"
 [ -z "${INSTALL_LIB}"     ] && INSTALL_LIB="${INSTALL} -m 0444"
+[ -z "${INSTALL_HDR}"     ] && INSTALL_HDR="${INSTALL} -m 0444"
 [ -z "${INSTALL_MAN}"     ] && INSTALL_MAN="${INSTALL} -m 0444"
 [ -z "${INSTALL_DATA}"    ] && INSTALL_DATA="${INSTALL} -m 0444"
 
@@ -625,6 +627,7 @@ MANM_TBL	= ${MANM_TBL}
 INSTALL		= ${INSTALL}
 INSTALL_PROGRAM	= ${INSTALL_PROGRAM}
 INSTALL_LIB	= ${INSTALL_LIB}
+INSTALL_HDR	= ${INSTALL_HDR}
 INSTALL_MAN	= ${INSTALL_MAN}
 INSTALL_DATA	= ${INSTALL_DATA}
 LN		= ${LN}