diff --git a/src/cligen/flag.cr b/src/cligen/flag.cr
index cb8ce08..9c1fc9b 100644
--- a/src/cligen/flag.cr
+++ b/src/cligen/flag.cr
@@ -68,11 +68,11 @@ module CliGen
       @format     : ::Regex? = nil
       )
       {% unless T.has_method? :to_s %}
-        {% raise "ERROR : Flag({{T}}, long: #{long}) : Error your flag type must have a to_s method" %}
+        {% raise "ERROR : Flag({{T}}) : Error your flag type must have a to_s method" %}
       {% end %}
       {% if T <= Array %}
         {% elem = T.type_vars.first %}
-        {% raise "ERROR : Flag({{T}}, long: #{long}) : Error your flag subtype must have a to_s method" unless elem.has_method? :to_s %}
+        {% raise "ERROR : Flag({{T}}) : Error your flag subtype must have a to_s method" unless elem.has_method? :to_s %}
       {% end %}
       meta = FlagMeta.new(
         type: {{T.stringify}},