diff --git a/math/algae/Makefile b/math/algae/Makefile
index 2ee12115354c..385a737f6ad6 100644
--- a/math/algae/Makefile
+++ b/math/algae/Makefile
@@ -1,31 +1,32 @@
 PORTNAME=	algae
 PORTVERSION=	4.3.6
-PORTREVISION=	19
+PORTREVISION=	20
 CATEGORIES=	math
 MASTER_SITES=	SF/${PORTNAME}/${PORTNAME}/${PORTNAME}-${PORTVERSION}
 
 MAINTAINER=	ports@FreeBSD.org
 COMMENT=	Programming language for numerical analysis
 WWW=		https://algae.sourceforge.net/
 
 LICENSE=	GPLv2+
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BROKEN_aarch64=		does not build: checking for proper floating point exception handling... no
 BROKEN_armv6=		does not build: checking for proper floating point exception handling... no
 BROKEN_armv7=		does not build: checking for proper floating point exception handling... no
 
 GNU_CONFIGURE=	yes
+GNU_CONFIGURE_MANPREFIX=${PREFIX}/share
 USES=		fortran
 
 CONFIGURE_ARGS=	--disable-dlmalloc --without-fftw --without-blas \
 		--without-lapack --without-bcslib --without-npsol
 FFLAGS+=	-std=legacy
 PLIST_SUB=	ALGAE_VERSION=${PORTVERSION}
 
 INFO=		${PORTNAME}
 
 post-install:
 	${STRIP_CMD} ${STAGEDIR}${PREFIX}/bin/${PORTNAME}-${PORTVERSION}
 
 .include <bsd.port.mk>
diff --git a/math/algae/files/patch-Makefile.in b/math/algae/files/patch-Makefile.in
index bbf7d884017a..195835aec738 100644
--- a/math/algae/files/patch-Makefile.in
+++ b/math/algae/files/patch-Makefile.in
@@ -1,153 +1,153 @@
 --- Makefile.in.orig	2003-12-06 21:39:23 UTC
 +++ Makefile.in
 @@ -78,7 +78,7 @@ datadir = $(prefix)/share
  libdir = $(prefix)/lib
  
  # Directory in which to install the man page.
 -mandir = $(datadir)/man/man$(manext)
-+mandir = $(prefix)/man/man$(manext)
++mandir = $(prefix)/share/man/man$(manext)
  # The manpage extension
  manext = 1
  
 @@ -150,19 +150,19 @@ configure: configure.in
  # Compile the source code.
  
  source: @BLAS@ @LAPACK@
 -	cd superlu; $(MAKE) RC0=$(RC0)
 -	cd arpack; $(MAKE)
 -	cd src; $(MAKE) RC0=$(RC0)
 +	$(MAKE) -C superlu RC0=$(RC0)
 +	$(MAKE) -C arpack
 +	$(MAKE) -C src RC0=$(RC0)
  .PHONY: source
  
  # Compile the BLAS and LAPACK libraries, if required.
  
  xblas:
 -	cd blas; $(MAKE)
 +	$(MAKE) -C blas
  .PHONY: xblas
  
  xlapack:
 -	cd lapack; $(MAKE)
 +	$(MAKE) -C lapack
  .PHONY: xlapack
  
  check: source
 @@ -180,13 +180,13 @@ algae.A: rc0
  # Run test cases.
  
  check:
 -	cd test; $(MAKE)
 +	$(MAKE) -C test
  .PHONY: check
  
  # Run some simple timing tests.
  
  times:
 -	cd timing; $(MAKE)
 +	$(MAKE) -C timing
  .PHONY: times
  
  # <<<< This section is deleted in the "binary" distribution.
 @@ -194,11 +194,11 @@ times:
  # Make documentation.
  
  info:
 -	cd doc; $(MAKE) info
 +	$(MAKE) -C doc info
  .PHONY: info
  
  dvi:
 -	cd doc; $(MAKE) dvi
 +	$(MAKE) -C doc dvi
  .PHONY: dvi
  
  # ========================== Distribution =========================
 @@ -211,9 +211,7 @@ dist:	distdir
  	  ln $$file $(distdir) > /dev/null 2>&1 || cp $$file $(distdir); \
  	done
  	for dir in $(SUBDIRS); do \
 -	  cd $${dir}; \
 -	  $(MAKE) distdir=../$(distdir)/$$dir dist; \
 -	  cd ..; \
 +	  $(MAKE) -C $${dir} distdir=../$(distdir)/$$dir dist; \
  	done
  	mv $(distdir) algae-$(VERSION_NUMBER)
  	tar chf algae-$(VERSION_NUMBER).tar algae-$(VERSION_NUMBER)
 @@ -230,9 +228,7 @@ binaries: bindistdir
  	done
  	awk '/<<[<]</,/>>[>]>/ {next} {print}' Makefile > $(distdir)/Makefile
  	for dir in $(BINSUBDIRS); do \
 -	  cd $${dir}; \
 -	  $(MAKE) distdir=../$(distdir)/$$dir binaries; \
 -	  cd ..; \
 +	  $(MAKE) -C $${dir} distdir=../$(distdir)/$$dir binaries; \
  	done
  	mv $(distdir) algae-$(VERSION_NUMBER)
  	tar chf algae-$(VERSION_NUMBER)-@host@.tar algae-$(VERSION_NUMBER)
 @@ -249,8 +245,8 @@ web:
  	for file in $(WEBDISTFILES); do \
  	  ln $$file $(distdir) > /dev/null 2>&1 || cp $$file $(distdir); \
  	done
 -	cd doc; $(MAKE) distdir=../$(distdir) web
 -	cd $(distdir); tar chf ../algae-web-$(VERSION_NUMBER).tar .
 +	$(MAKE) -C doc distdir=../$(distdir) web
 +	tar -C $(distdir) -chf ../algae-web-$(VERSION_NUMBER).tar .
  	rm -rf $(distdir)
  	gzip algae-web-$(VERSION_NUMBER).tar
  .PHONY: web
 @@ -278,7 +274,7 @@ maintainer-clean::
  	@echo "it deletes files that may require special tools to rebuild."
  
  clean mostlyclean distclean maintainer-clean::
 -	for dir in $(SUBDIRS); do cd $${dir}; $(MAKE) $@; cd ..; done
 +	for dir in $(SUBDIRS); do $(MAKE) -C $${dir} $@; done
  
  clean mostlyclean distclean maintainer-clean::
  	rm -f a.out core conft* algae-*.tar algae-*.tar.gz
 @@ -294,15 +290,12 @@ install: all
  # >>>> End of deleted section.
  
  install: algae.A installdirs
 -	$(INSTALL_DATA) algae.A $(RC0)
 -	$(INSTALL_DATA) COPYING $(htmldir)
 -	$(INSTALL_DATA) LICENSE $(htmldir)
 -	cd src; \
 -	  $(MAKE) bindir=$(bindir) install
 -	cd tools; \
 -	  $(MAKE) tooldir=$(tooldir) install
 -	cd doc; \
 -	  $(MAKE) mandir=$(mandir) datadir=$(datadir) \
 +	$(INSTALL_DATA) algae.A $(DESTDIR)$(RC0)
 +	$(INSTALL_DATA) COPYING $(DESTDIR)$(htmldir)
 +	$(INSTALL_DATA) LICENSE $(DESTDIR)$(htmldir)
 +	$(MAKE) -C src bindir=$(bindir) install
 +	$(MAKE) -C tools tooldir=$(tooldir) install
 +	$(MAKE) -C doc mandir=$(mandir) datadir=$(datadir) \
  	  manext=$(manext) infodir=$(infodir) htmldir=$(htmldir) install
  .PHONY:	install
  
 @@ -310,17 +303,17 @@ install: algae.A installdirs
  # if necessary.
  
  installdirs: mkinstalldirs
 -	$(srcdir)/mkinstalldirs $(bindir) $(datadir) $(libdir) $(infodir) \
 -          $(mandir) $(tooldir) $(rcdir) $(htmldir)
 +	$(srcdir)/mkinstalldirs $(DESTDIR)$(bindir) $(DESTDIR)$(datadir) $(DESTDIR)$(libdir) $(DESTDIR)$(infodir) \
 +          $(DESTDIR)$(mandir) $(DESTDIR)$(tooldir) $(DESTDIR)$(rcdir) $(DESTDIR)$(htmldir)
  .PHONY:	installdirs
  
  # Why would anyone want to uninstall?
  
  uninstall:
  	rm -f $(RC0)
 -	cd src; $(MAKE) bindir=$(bindir) uninstall
 -	cd tools; $(MAKE) tooldir=$(tooldir) uninstall
 -	cd doc; $(MAKE) mandir=$(mandir) manext=$(manext) \
 +	$(MAKE) -C src bindir=$(bindir) uninstall
 +	$(MAKE) -C tools tooldir=$(tooldir) uninstall
 +	$(MAKE) -C doc mandir=$(mandir) manext=$(manext) \
  	  infodir=$(infodir) htmldir=$(htmldir) uninstall
  	rm -f $(htmldir)/COPYING $(htmldir)/LICENSE
  	-rmdir $(rcdir) $(htmldir) $(tooldir) \
diff --git a/math/algae/pkg-plist b/math/algae/pkg-plist
index fd1de8b61cb4..bdf0ef5ded8a 100644
--- a/math/algae/pkg-plist
+++ b/math/algae/pkg-plist
@@ -1,89 +1,89 @@
 bin/algae
 bin/algae-%%ALGAE_VERSION%%
 lib/algae/%%ALGAE_VERSION%%/algae.A
-man/man1/algae.1.gz
+share/man/man1/algae.1.gz
 %%DATADIR%%/%%ALGAE_VERSION%%/html/COPYING
 %%DATADIR%%/%%ALGAE_VERSION%%/html/LICENSE
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_1.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_10.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_11.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_12.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_13.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_14.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_15.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_16.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_2.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_3.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_4.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_5.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_6.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_7.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_8.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_9.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_abt.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/algae_toc.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/icon.gif
 %%DATADIR%%/%%ALGAE_VERSION%%/html/index.html
 %%DATADIR%%/%%ALGAE_VERSION%%/html/info.db
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/all.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/arg.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/autosrc.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/brent.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/circshift.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/combine.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/diff.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/equal.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/eval.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/first.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/gcd.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/grep.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/help.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/ident.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/info.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/inv.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/label.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/last.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/lcm.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/load.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/log10.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/logspace.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/magic.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/max.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/merge.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/message.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/monte.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/mult.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/ode4.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/pick.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/plot.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/primes.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/product.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/prof.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/provide.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/randn.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/require.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/reverse.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/roots.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/save.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/select.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/seq.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/shape.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/show.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/sign.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/solve.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/sources.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/spline.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/src.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/ssi.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/string.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/sum.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/surprise.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/tmp_file.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/trapz.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/tools.algae
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/umin.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/unlabel.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/what.A
 %%DATADIR%%/%%ALGAE_VERSION%%/tools/who.A
 %%DATADIR%%/html