diff -Naur source-old/higan-ui/GNUmakefile source-new/higan-ui/GNUmakefile
--- source-old/higan-ui/GNUmakefile	1969-12-31 21:00:01.000000000 -0300
+++ source-new/higan-ui/GNUmakefile	2021-09-29 22:35:35.744721052 -0300
@@ -61,7 +61,7 @@
 	mkdir -p $(output.path)/$(name).app/Contents/Resources/
 	mv $(output.path)/$(name) $(output.path)/$(name).app/Contents/MacOS/$(name)
 	cp resource/$(name).plist $(output.path)/$(name).app/Contents/Info.plist
-	sips -s format icns resource/$(name).png --out $(output.path)/$(name).app/Contents/Resources/$(name).icns
+	png2icns $(output.path)/$(name).app/Contents/Resources/$(name).icns resource/$(name).png
 endif
 
 verbose: nall.verbose ruby.verbose hiro.verbose all;
diff -Naur source-old/icarus/GNUmakefile source-new/icarus/GNUmakefile
--- source-old/icarus/GNUmakefile	1969-12-31 21:00:01.000000000 -0300
+++ source-new/icarus/GNUmakefile	2021-09-29 22:35:53.639846113 -0300
@@ -26,7 +26,7 @@
 	mkdir -p $(output.path)/$(name).app/Contents/Resources/
 	mv $(output.path)/$(name) $(output.path)/$(name).app/Contents/MacOS/$(name)
 	cp resource/$(name).plist $(output.path)/$(name).app/Contents/Info.plist
-	sips -s format icns resource/$(name).png --out $(output.path)/$(name).app/Contents/Resources/$(name).icns
+	png2icns $(output.path)/$(name).app/Contents/Resources/$(name).icns resource/$(name).png
 endif
 
 verbose: hiro.verbose nall.verbose all;