text: diff --git a/data/Makefile b/data/Makefile
  index 8c6470f..e0f3aa2 100644
  --- a/data/Makefile
  +++ b/data/Makefile
  @@ -9,13 +9,14 @@ RUBY=ruby
   PERL=perl
   MAKE=make
   JULIA=julia
  -CURLFLAGS = --retry 5 --location
  +FONTFORGE=fontforge
  +CURLFLAGS = --retry 5 --location --insecure
   
   .PHONY: clean
   
   .DELETE_ON_ERROR:
   
  -utf8proc_data.c.new: data_generator.rb UnicodeData.txt GraphemeBreakProperty.txt DerivedCoreProperties.txt CompositionExclusions.txt CaseFolding.txt CharWidths.txt emoji-data.txt
  +utf8proc_data.c.new: data_generator.rb UnicodeData.txt GraphemeBreakProperty.txt DerivedCoreProperties.txt CompositionExclusions.txt CaseFolding.txt GraphemeBreakTest.txt emoji-data.txt unifont.ttf unifont_upper.ttf unifont.sfd unifont_upper.sfd CharWidths.txt
   	$(RUBY) data_generator.rb < UnicodeData.txt > $@
   
   CharWidths.txt: charwidths.jl EastAsianWidth.txt
  @@ -24,33 +25,46 @@ CharWidths.txt: charwidths.jl EastAsianWidth.txt
   # Unicode data version (must also update utf8proc_unicode_version function)
   UNICODE_VERSION=13.0.0
   
  +# Grab the corresponding GNU Unifont files in case we need to render a character.
  +UNIFONT_VERSION=13.0.02
  +
   UnicodeData.txt:
  -	$(CURL) $(CURLFLAGS) -o $@ -O http://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/UnicodeData.txt
  +	$(CURL) $(CURLFLAGS) -o $@ https://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/UnicodeData.txt
   
   EastAsianWidth.txt:
  -	$(CURL) $(CURLFLAGS) -o $@ -O $(URLCACHE)http://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/EastAsianWidth.txt
  +	$(CURL) $(CURLFLAGS) -o $@ https://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/EastAsianWidth.txt
   
   GraphemeBreakProperty.txt:
  -	$(CURL) $(CURLFLAGS) -o $@ -O $(URLCACHE)http://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/auxiliary/GraphemeBreakProperty.txt
  +	$(CURL) $(CURLFLAGS) -o $@ https://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/auxiliary/GraphemeBreakProperty.txt
   
   DerivedCoreProperties.txt:
  -	$(CURL) $(CURLFLAGS) -o $@ -O $(URLCACHE)http://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/DerivedCoreProperties.txt
  +	$(CURL) $(CURLFLAGS) -o $@ https://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/DerivedCoreProperties.txt
   
   CompositionExclusions.txt:
  -	$(CURL) $(CURLFLAGS) -o $@ -O $(URLCACHE)http://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/CompositionExclusions.txt
  +	$(CURL) $(CURLFLAGS) -o $@ https://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/CompositionExclusions.txt
   
   CaseFolding.txt:
  -	$(CURL) $(CURLFLAGS) -o $@ -O $(URLCACHE)http://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/CaseFolding.txt
  +	$(CURL) $(CURLFLAGS) -o $@ https://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/CaseFolding.txt
   
   NormalizationTest.txt:
  -	$(CURL) $(CURLFLAGS) -o $@ -O $(URLCACHE)http://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/NormalizationTest.txt
  +	$(CURL) $(CURLFLAGS) -o $@ https://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/NormalizationTest.txt
   
   GraphemeBreakTest.txt:
  -	$(CURL) $(CURLFLAGS) $(URLCACHE)http://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/auxiliary/GraphemeBreakTest.txt | $(PERL) -pe 's,÷,/,g;s,×,+,g' > $@
  +	$(CURL) $(CURLFLAGS) https://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/auxiliary/GraphemeBreakTest.txt | $(PERL) -pe 's,÷,/,g;s,×,+,g' > $@
   
   emoji-data.txt:
  -	$(CURL) $(CURLFLAGS) -o $@ -O $(URLCACHE)http://unicode.org/Public/$(UNICODE_VERSION)/ucd/emoji/emoji-data.txt
  +	$(CURL) $(CURLFLAGS) -o $@ http://unicode.org/Public/$(UNICODE_VERSION)/ucd/emoji/emoji-data.txt
  +
  +unifont.ttf:
  +	$(CURL) $(CURLFLAGS) -o $@ https://mirrors.kernel.org/gnu/unifont/unifont-$(UNIFONT_VERSION)/unifont-$(UNIFONT_VERSION).ttf
  +
  +unifont_upper.ttf:
  +	$(CURL) $(CURLFLAGS) -o $@ https://mirrors.kernel.org/gnu/unifont/unifont-$(UNIFONT_VERSION)/unifont_upper-$(UNIFONT_VERSION).ttf
  +
  +%.sfd: %.ttf
  +	$(FONTFORGE) -lang=ff -c "Open(\"$<\");Save(\"$@\");Quit(0);"
   
   clean:
   	rm -f UnicodeData.txt EastAsianWidth.txt GraphemeBreakProperty.txt DerivedCoreProperties.txt CompositionExclusions.txt CaseFolding.txt NormalizationTest.txt GraphemeBreakTest.txt CharWidths.txt emoji-data.txt
  +	rm -f unifont.ttf unifont_upper.ttf unifont.sfd unifont_upper.sfd
   	rm -f utf8proc_data.c.new
  