diff '--color=auto' --unified --recursive --text src/vulkan-man-pages-1.3.268/Makefile src2/vulkan-man-pages-1.3.268/Makefile
--- src/vulkan-man-pages-1.3.268/Makefile	2021-05-24 02:23:32.000000000 -0500
+++ src2/vulkan-man-pages-1.3.268/Makefile	2021-06-02 17:30:19.571260784 -0500
@@ -435,7 +435,7 @@
 
 # Build the individual refpages, then the symbolic links from aliases
 MANHTMLDIR  = $(OUTDIR)/man/html
-MANHTML     = $(MANSOURCES:$(REFPATH)/%.adoc=$(MANHTMLDIR)/%.html)
+MANHTML     = $(MANSOURCES:$(REFPATH)/%.adoc=$(MANHTMLDIR)/%.3)
 buildmanpages: $(MANHTML)
 	$(MAKE) $(SUBMAKEOPTIONS) -e manaliases
 
@@ -455,11 +455,11 @@
 # use VERYQUIET instead of QUIET
 # Running translate_math.js on every refpage is slow and most of them
 # do not contain math, so do a quick search for latexmath delimiters.
-$(MANHTMLDIR)/%.html: KATEXDIR = ../../katex
-$(MANHTMLDIR)/%.html: $(REFPATH)/%.adoc $(GENDEPENDS) $(KATEXINSTDIR)
+$(MANHTMLDIR)/%.3: KATEXDIR = ../../katex
+$(MANHTMLDIR)/%.3: $(REFPATH)/%.adoc $(GENDEPENDS) $(KATEXINSTDIR)
 	$(VERYQUIET)echo "Building $@ from $< using default options"
 	$(VERYQUIET)$(MKDIR) $(MANHTMLDIR)
-	$(VERYQUIET)$(ASCIIDOC) -b html5 $(ADOCOPTS) $(ADOCHTMLOPTS) $(ADOCREFOPTS) \
+	$(VERYQUIET)$(ASCIIDOC) -b manpage $(ADOCOPTS) $(ADOCHTMLOPTS) $(ADOCREFOPTS) \
 	    -d manpage -o $@ $<
 	$(VERYQUIET)if egrep -q '\\[([]' $@ ; then \
 	    $(TRANSLATEMATH) $@ ; \