diff --git a/lib/ridl/type.rb b/lib/ridl/type.rb
index 930a947..143f479 100644
--- a/lib/ridl/type.rb
+++ b/lib/ridl/type.rb
@@ -263,10 +263,11 @@ class Fixed < Type
       attr_reader :digits, :scale
 
       def initialize(digits = nil, scale = nil)
+        raise "anonymous fixed definitions are not allowed!" if digits.nil? || scale.nil?
         raise "significant digits for Fixed should be in the range 0-31" unless digits.nil? || (0..31) === digits.to_i
 
-        @digits = digits.nil? ? digits : digits.to_i
-        @scale = scale.nil? ? scale : scale.to_i
+        @digits = digits.to_i
+        @scale = scale.to_i
       end
 
       def narrow(obj)