diff --git a/src/theme/syntaxes/README.md b/src/theme/syntaxes/README.md
index 2031f263..9f5175f5 100644
--- a/src/theme/syntaxes/README.md
+++ b/src/theme/syntaxes/README.md
@@ -1,6 +1,6 @@
 Console.sublime-syntax was written for mdBook.
 
-Handlebars.sublime-syntax is from PLACEHOLDER
+Handlebars.sublime-syntax is from https://github.com/daaain/Handlebars/blob/master/grammars/Handlebars.tmLanguage (it was converted to `sublime-syntax` using Sublime Text).
 
 TOML.sublime-syntax is from https://github.com/jasonwilliams/sublime_toml_highlighting/blob/0f14b7caf3c775a5d18551a9563a9debdb10c9a9/TOML.sublime-syntax