lib/expressive_grammar.treetop in expressive-0.0.25 vs lib/expressive_grammar.treetop in expressive-0.0.26

@@ -19,10 +19,10 @@
   rule value
     (string / boolean / number)
   end
 
   rule word
-    [a-zA-Z]+
+    [a-zA-Z0-9_]+
   end
 
   rule string
     '"' ([^"\\] / "\\" . )* '"' <StringValue>
   end