diff --git a/mode/ruby/ruby.js b/mode/ruby/ruby.js
index 5d9288666f..b84dde29e3 100644
--- a/mode/ruby/ruby.js
+++ b/mode/ruby/ruby.js
@@ -63,7 +63,7 @@ CodeMirror.defineMode("ruby", function(config) {
     } else if (ch == "#") {
       stream.skipToEnd();
       return "comment";
-    } else if (ch == "<" && (m = stream.match(/^<(-)?[\`\"\']?([a-zA-Z_?]\w*)[\`\"\']?(?:;|$)/))) {
+    } else if (ch == "<" && (m = stream.match(/^<([-~])[\`\"\']?([a-zA-Z_?]\w*)[\`\"\']?(?:;|$)/))) {
       return chain(readHereDoc(m[2], m[1]), stream, state);
     } else if (ch == "0") {
       if (stream.eat("x")) stream.eatWhile(/[\da-fA-F]/);