diff --git a/exercises/03/vslc/src/parser.y b/exercises/03/vslc/src/parser.y
index 1057d47..bb05a2a 100644
--- a/exercises/03/vslc/src/parser.y
+++ b/exercises/03/vslc/src/parser.y
@@ -250,13 +250,13 @@ expression:
       $$ = NODE(EXPRESSION, strdup("~"), 1, $2);
     }
   | '(' expression ')' {
-      $$ = NODE(EXPRESSION, NULL /*strdup("group")*/, 1, $2);
+      $$ = NODE(EXPRESSION, /*NULL*/ strdup("group"), 1, $2);
     }
   | number {
-      $$ = NODE(EXPRESSION, NULL /*strdup("number")*/, 1, $1);
+      $$ = NODE(EXPRESSION, /*NULL*/ strdup("number"), 1, $1);
     }
   | identifier {
-      $$ = NODE(EXPRESSION, NULL /*strdup("identifier")*/, 1, $1);
+      $$ = NODE(EXPRESSION, /*NULL*/ strdup("identifier"), 1, $1);
     }
   | identifier '(' argument_list ')' {
       $$ = NODE(EXPRESSION, /*NULL*/ strdup("function_call"), 2, $1, $3);