diff --git a/cmake/IconUtils.cmake b/cmake/IconUtils.cmake
index abd1f6a..c21cc4e 100644
--- a/cmake/IconUtils.cmake
+++ b/cmake/IconUtils.cmake
@@ -38,3 +38,47 @@ function (icon_for_win32 ico pngs pngs_raw)
 		DEPENDS ${pngs} ${pngs_raw}
 		COMMENT "Generating Windows program icon" VERBATIM)
 endfunction ()
+
+function (icon_to_iconset_size name svg size iconset outputs)
+	math (EXPR _size2x "${size} * 2")
+	set (_dimensions "${size}x${size}")
+	set (_png1x "${iconset}/icon_${_dimensions}.png")
+	set (_png2x "${iconset}/icon_${_dimensions}@2x.png")
+	set (${outputs} "${_png1x};${_png2x}" PARENT_SCOPE)
+
+	set (_find_program_REQUIRE)
+	if (NOT ${CMAKE_VERSION} VERSION_LESS 3.18.0)
+		set (_find_program_REQUIRE REQUIRED)
+	endif ()
+
+	find_program (rsvg_convert_EXECUTABLE rsvg-convert ${_find_program_REQUIRE})
+	add_custom_command (OUTPUT "${_png1x}" "${_png2x}"
+		COMMAND ${CMAKE_COMMAND} -E make_directory "${iconset}"
+		COMMAND ${rsvg_convert_EXECUTABLE} "--output=${_png1x}"
+			"--width=${size}" "--height=${size}" -- "${svg}"
+		COMMAND ${rsvg_convert_EXECUTABLE} "--output=${_png2x}"
+			"--width=${_size2x}" "--height=${_size2x}" -- "${svg}"
+		DEPENDS "${svg}"
+		COMMENT "Generating ${name} ${_dimensions} icons" VERBATIM)
+endfunction ()
+function (icon_to_icns svg output_basename output)
+	get_filename_component (_name "${output_basename}" NAME_WE)
+	set (_iconset "${PROJECT_BINARY_DIR}/${_name}.iconset")
+	set (_icon "${PROJECT_BINARY_DIR}/${output_basename}")
+	set (${output} "${_icon}" PARENT_SCOPE)
+
+	set (_icon_png_list)
+	foreach (_icon_size 16 32 128 256 512)
+		icon_to_iconset_size ("${_name}" "${svg}"
+			"${_icon_size}" "${_iconset}" _icon_pngs)
+		list (APPEND _icon_png_list ${_icon_pngs})
+	endforeach ()
+
+	# XXX: This will not normally work from within Nix.
+	add_custom_command (OUTPUT "${_icon}"
+		COMMAND iconutil -c icns -o "${_icon}" "${_iconset}"
+		DEPENDS ${_icon_png_list}
+		COMMENT "Generating ${_name} icon" VERBATIM)
+	set_source_files_properties ("${_icon}" PROPERTIES
+		MACOSX_PACKAGE_LOCATION Resources)
+endfunction ()