diff --git a/src/cligen/command/argument.cr b/src/cligen/command/argument.cr
index f564264..426066e 100644
--- a/src/cligen/command/argument.cr
+++ b/src/cligen/command/argument.cr
@@ -5,7 +5,7 @@ module CliGen
       {% raise "ERROR : CliGen::Command.argument : First argument (#{variable}) must be a TypeDeclaration (ex: '<var> : <type> [= val]')" unless variable.is_a? TypeDeclaration %}
       {% name = variable.var %}
       {% type = variable.type %}
-      {% if type <= Array %}
+      {% if type.resolve <= Array %}
         {% delimiter = "," unless delimiter.is_a? StringLiteral %}
       {% end %}
       {% if short %}