diff --git a/lib/parser/call_site.rb b/lib/parser/call_site.rb
index df7aeef..b1c3f42 100644
--- a/lib/parser/call_site.rb
+++ b/lib/parser/call_site.rb
@@ -2,17 +2,19 @@ module Parser
   module CallSite
     include Parslet
 
+    rule(:field_access) { name.as(:receiver) >> str(".") >> name.as(:field) }
+
+    rule(:r_value) { call_site | field_access | basic_type }
+
     rule(:argument_list) {
       left_parenthesis >>
       (  (basic_type.as(:argument) >>
-          (comma >> basic_type.as(:argument)).repeat(0)).repeat(0,1)).as(:argument_list) >>
+          (comma >> r_value.as(:argument)).repeat(0)).repeat(0,1)).as(:argument_list) >>
            right_parenthesis
     }
 
     rule(:call_site) { (basic_type.as(:receiver) >> str(".")).maybe >> #possibly qualified
                           name.as(:call_site) >> argument_list >> comment.maybe}
 
-    rule(:field_access) { name.as(:receiver) >> str(".") >> name.as(:field) }
-
   end
 end
diff --git a/lib/parser/expression.rb b/lib/parser/expression.rb
index 2ab0f48..a274407 100644
--- a/lib/parser/expression.rb
+++ b/lib/parser/expression.rb
@@ -2,8 +2,6 @@ module Parser
   module Expression
     include Parslet
 
-    rule(:r_value) { call_site | field_access |basic_type }
-
     rule(:expression) { (simple_return | while_do | small_conditional | conditional |
                           operator_expression | call_site | class_field | field |
                           hash_constant | array_constant)  }