diff -r 5ec05bde6098 nml/grfstrings.py
--- a/nml/grfstrings.py	Sun Oct 16 19:30:32 2016 +0200
+++ b/nml/grfstrings.py	Fri Dec 09 20:16:27 2016 +0100
@@ -161,7 +161,8 @@
 
 def com_parse_string(val, lang_id):
     import nml.expression
-    if not isinstance(val, (nml.expression.StringLiteral, nml.expression.String)):
+    # Check for string, string literal or integer (TTD_STR_xxx)
+    if not isinstance(val, (nml.expression.StringLiteral, nml.expression.String, nml.expression.ConstantNumeric)):
         raise generic.ScriptError("Expected a (literal) string", val.pos)
     if isinstance(val, nml.expression.String):
         # Check that the string exists