diff --git a/rake.d/iso639.rb b/rake.d/iso639.rb
index ab6b91891..799233271 100644
--- a/rake.d/iso639.rb
+++ b/rake.d/iso639.rb
@@ -1,31 +1,47 @@
 def create_iso639_language_list_file
-  cpp_file_name = "src/common/iso639_language_list.cpp"
-  iso639_2      = JSON.parse(IO.readlines("/usr/share/iso-codes/json/iso_639-2.json").join('')) \
-    ["639-2"].
-    reject { |entry| %r{^qaa}.match(entry["alpha_3"]) }.
-    map do |entry|
-      entry["has_639_2"]      = true
-      entry["alpha_3_to_use"] = entry["bibliographic"] || entry["alpha_3"]
-      entry
-    end
-
-  used_codes = Hash[ *iso639_2.map { |entry| [ entry["alpha_3"], true, entry["bibliographic"], true ] }.flatten ]
-
-  JSON.parse(IO.readlines("/usr/share/iso-codes/json/iso_639-3.json").join('')) \
-    ["639-3"].
-    reject { |entry| entry["type"] != "L" }.
-    reject { |entry| used_codes.include?(entry["alpha_3"]) }.
-    each do |entry|
-      iso639_2 << {
-        "name"           => entry["name"],
-        "alpha_3"        => entry["alpha_3"],
-        "alpha_3_to_use" => entry["alpha_3"],
-        "has_639_2"      => false,
-      }
-    end
-
-  rows = iso639_2.
+  list_file       = "iso-639-3"
+  list_downloaded = false
+
+  if !FileTest.exists?(list_file)
+    url = "https://iso639-3.sil.org/sites/iso639-3/files/downloads/iso-639-3.tab"
+    runq "wget", url, "wget --quiet -O #{list_file} #{url}"
+
+    list_downloaded = true
+  end
+
+  lines   = IO.readlines(list_file).map(&:chomp)
+  headers = Hash[ *
+    lines.
+    shift.
+    split(%r{\t}).
+    map(&:downcase).
+    each_with_index.
+    map { |name, index| [ index, name ] }.
+    flatten
+  ]
+
+  rows = lines.
+    map do |line|
+    parts = line.split(%r{\t})
+    entry = Hash[ *
+      (0..parts.size).
+      map { |idx| [ headers[idx], !parts[idx] || parts[idx].empty? ? nil : parts[idx] ] }.
+      flatten
+    ]
+
+    entry
+  end.
+    reject { |entry| !%r{^[CLS]$}.match(entry["language_type"]) }. # Constructed, Living & Special
     map do |entry|
+    {
+      "name"           => entry["ref_name"],
+      "bibliographic"  => entry["part2b"] && (entry["part2b"] != entry["part2t"]) ? entry["part2b"] : nil,
+      "alpha_2"        => entry["part1"],
+      "alpha_3"        => entry["part2t"] || entry["id"],
+      "alpha_3_to_use" => entry["part2b"] || entry["id"],
+      "has_639_2"      => !entry["part2b"].nil?,
+    }
+  end.map do |entry|
     [ entry["name"].to_u8_cpp_string,
       entry["alpha_3_to_use"].to_cpp_string,
       (entry["alpha_2"] || '').to_cpp_string,
@@ -81,7 +97,11 @@ EOT
 } // namespace mtx::iso639
 EOT
 
-  content = header + format_table(rows.sort, :column_suffix => ',', :row_prefix => "  g_languages.emplace_back(", :row_suffix => ");").join("\n") + "\n" + footer
+  content       = header + format_table(rows.sort, :column_suffix => ',', :row_prefix => "  g_languages.emplace_back(", :row_suffix => ");").join("\n") + "\n" + footer
+  cpp_file_name = "src/common/iso639_language_list.cpp"
 
   runq("write", cpp_file_name) { IO.write("#{$source_dir}/#{cpp_file_name}", content); 0 }
+
+ensure
+  File.unlink(list_file) if list_downloaded && FileTest.exists?(list_file)
 end