diff --git a/build/development-tools/add_po.rb b/build/development-tools/add_po.rb
index 099642420..1717b83e3 100755
--- a/build/development-tools/add_po.rb
+++ b/build/development-tools/add_po.rb
@@ -2,6 +2,7 @@
 # coding: utf-8
 
 require "fileutils"
+require "pathname"
 require "shellwords"
 require "tmpdir"
 
@@ -50,11 +51,56 @@ module AddPo
     fail "bsdtar failed for #{file_name}" unless $?.exitstatus == 0
   end
 
+  def self.handle_qm file_name
+    Dir.mktmpdir do |dir|
+      tm_name = Pathname.new(file_name).basename.sub_ext(".tm").to_s
+      system "lconvert -i #{Shellwords.escape(file_name)} -o #{Shellwords.escape(tm_name)}"
+
+      fail "lconvert failed for #{file_name}" unless $?.exitstatus == 0
+
+      handle_ts tm_name
+
+      File.unlink file_name
+    end
+  end
+
+  def self.handle_ts file_name, language = nil
+    content   = IO.
+      readlines(file_name).
+      map(&:chomp)
+
+    language = content.
+      map { |line| /<TS [^>]* language="([a-z_@]+)"/ix.match(line) ? $1 : nil }.
+      compact.
+      first
+
+    if !language
+      language = ENV['TS'] if ENV['TS'] && !ENV['TS'].empty?
+      language = $1        if !language && /qtbase_([a-zA-Z_@]+)/.match(file_name)
+    end
+
+    fail "Unknown language for Qt TS file #{file_name} (set TS)" if !language
+
+    target = "#{$po_dir}/qt/qtbase_#{language}.ts"
+
+    if !FileTest.exists?(target) && /^([a-z]+)_[a-z]+/i.match(language)
+      target = "#{$po_dir}/qt/qtbase_#{$1}.ts"
+    end
+
+    fail "target file does not exist yet: #{target} (wrong language?)" if !FileTest.exists?(target)
+
+    File.open(target, "w") { |file| file.puts content.map(&:chomp).join("\n") }
+    File.unlink file_name
+    File.chmod 0644, target
+  end
+
   def self.handle_archive file_name, archive_type
     Dir.mktmpdir do |dir|
       Dir.chdir(dir) do
         send "unpack_#{archive_type}".to_sym, file_name
         Dir["**/*.po"].each { |unpacked_file| handle_po unpacked_file }
+        Dir["**/*.qm"].each { |unpacked_file| handle_qm unpacked_file }
+        Dir["**/*.ts"].each { |unpacked_file| handle_ts unpacked_file }
       end
     end
 
@@ -67,6 +113,8 @@ module AddPo
     return handle_archive(file_name, :p7z) if /\.7z$/i.match  file_name
     return handle_archive(file_name, :tar) if /\.tar(?:\.(?:gz|bz2|xz))?$/i.match  file_name
     return handle_po(file_name)            if /\.po$/i.match  file_name
+    return handle_qm(file_name)            if /\.qm$/i.match  file_name
+    return handle_ts(file_name)            if /\.ts$/i.match  file_name
     fail "Don't know how to handle #{file_name}"
   end
 end