diff --git a/demo/arg_parser_demo.cc b/demo/arg_parser_demo.cc
--- a/demo/arg_parser_demo.cc
+++ b/demo/arg_parser_demo.cc
@@ -46,7 +46,7 @@
     .refOption("grb","Choice B",g2)
     .refOption("grc","Choice C",g3)
     .optionGroup("gr","gra")
-    .optionGroup("gr","grbkk")
+    .optionGroup("gr","grb")
     .optionGroup("gr","grc")
     .mandatoryGroup("gr")
     .onlyOneGroup("gr")