diff --git a/Dockerfile b/Dockerfile
index 0632057..8269880 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM danysk/docker-manjaro-texlive-ruby:15.0.39
+FROM danysk/docker-manjaro-texlive-ruby:15.0.119
 COPY entrypoint.rb entrypoint.rb
 RUN ruby -c entrypoint.rb
 RUN chmod +x entrypoint.rb
diff --git a/entrypoint.rb b/entrypoint.rb
index 38380c5..99485f6 100755
--- a/entrypoint.rb
+++ b/entrypoint.rb
@@ -24,7 +24,7 @@ def warn(file, message)
 puts "Found these tex files: #{tex_files}" if verbose
 magic_comment_matcher = /^\s*%\s*!\s*[Tt][Ee][xX]\s*root\s*=\s*(.*\.[Tt][Ee][xX]).*$/
 tex_roots = tex_files.filter_map do |file|
-    text = File.read(file)
+    text = File.read(file, :encoding => 'UTF-8')
     match = text[magic_comment_matcher, 1]
     if match then
         puts("File #{file} matched a magic comment pointing to #{match}")