diff --git a/src/backends/lalr.c b/src/backends/lalr.c
index 3c841691c404bda0883b1b653440322d1852e8e4..272f00d6c598e59bdf253363c8f4440e619e47e3 100644
--- a/src/backends/lalr.c
+++ b/src/backends/lalr.c
@@ -52,7 +52,7 @@ static void transform_productions(const HLRTable *table, HLREnhGrammar *eg,
   if (xAy->type != HCF_CHOICE) {
     return;
   }
-  // XXX CHARSET?
+  // NB: nothing to do on quasi-terminal CHARSET which carries no list of rhs's
 
   HArena *arena = eg->arena;