diff --git a/scripts/build b/scripts/build
index fabec033..352ff8da 100755
--- a/scripts/build
+++ b/scripts/build
@@ -135,8 +135,15 @@ def transform_patterns(heuristics)
 end
 
 def load_languages
-  url = "#{BASE_URL}/lib/linguist/languages.yml"
-  data = URI.open(url) { |io| YAML.load(io.read) }
+  file = 'tmp/languages.yml'
+
+  unless File.exist?(file)
+    url = "#{BASE_URL}/lib/linguist/languages.yml"
+    data = URI.open(url) { |io| io.read }
+    File.write(file, data)
+  end
+
+  YAML.load(File.read(file))
 end
 
 def parse_remote(remote)
diff --git a/syntax/rust.vim b/syntax/rust.vim
index 2ad37ed8..a5f312be 100644
--- a/syntax/rust.vim
+++ b/syntax/rust.vim
@@ -231,7 +231,7 @@ syn region rustCommentBlockDocNestError matchgroup=rustCommentBlockDocError star
 " then you must deal with cases like ``/*/**/*/``. And don't try making it
 " worse with ``\%(/\@<!\*\)\@<!``, either...
 
-syn keyword rustTodo contained TODO FIXME XXX NB NOTE
+syn keyword rustTodo contained TODO FIXME XXX NB NOTE SAFETY
 
 " asm! macro {{{2
 syn region rustAsmMacro matchgroup=rustMacro start="\<asm!\s*(" end=")" contains=rustAsmDirSpec,rustAsmSym,rustAsmConst,rustAsmOptionsGroup,rustComment.*,rustString.*