diff --git a/lib/protector/adapters/active_record/base.rb b/lib/protector/adapters/active_record/base.rb
index 9a87a0c..e17297a 100644
--- a/lib/protector/adapters/active_record/base.rb
+++ b/lib/protector/adapters/active_record/base.rb
@@ -63,11 +63,9 @@ def [](name)
         module ClassMethods
           # Storage of {Protector::DSL::Meta}
           def protector_meta
-            @protector_meta ||= Protector::DSL::Meta.new(
-              Protector::Adapters::ActiveRecord,
-              self,
+            @protector_meta ||= Protector::DSL::Meta.new(Protector::Adapters::ActiveRecord, self) do
               self.column_names
-            )
+            end
           end
 
           # Wraps every `.field` method with a check against {Protector::DSL::Meta::Box#readable?}
diff --git a/lib/protector/adapters/sequel/model.rb b/lib/protector/adapters/sequel/model.rb
index 561356a..a8bddb2 100644
--- a/lib/protector/adapters/sequel/model.rb
+++ b/lib/protector/adapters/sequel/model.rb
@@ -18,11 +18,9 @@ def restrict!(*args)
         module ClassMethods
           # Storage of {Protector::DSL::Meta}
           def protector_meta
-            @protector_meta ||= Protector::DSL::Meta.new(
-              Protector::Adapters::Sequel,
-              self,
+            @protector_meta ||= Protector::DSL::Meta.new(Protector::Adapters::Sequel, self) do
               self.columns
-            )
+            end
           end
 
           # Gets default restricted `Dataset`
diff --git a/lib/protector/dsl.rb b/lib/protector/dsl.rb
index a82fd00..4c93a72 100644
--- a/lib/protector/dsl.rb
+++ b/lib/protector/dsl.rb
@@ -214,10 +214,14 @@ def modifiable?(part, fields)
         end
       end
 
-      def initialize(adapter, model, fields)
-        @adapter = adapter
-        @model   = model
-        @fields  = fields
+      def initialize(adapter, model, &fields_proc)
+        @adapter     = adapter
+        @model       = model
+        @fields_proc = fields_proc
+      end
+
+      def fields
+        @fields ||= @fields_proc.call
       end
 
       # Storage for `protect` blocks
@@ -235,7 +239,7 @@ def <<(block)
       # @param subject [Object]           Restriction subject
       # @param entry [Object]             An instance of the model
       def evaluate(subject, entry=nil)
-        Box.new(@adapter, @model, @fields, subject, entry, blocks)
+        Box.new(@adapter, @model, fields, subject, entry, blocks)
       end
     end
 
diff --git a/lib/protector/version.rb b/lib/protector/version.rb
index 8232f29..6d23d08 100644
--- a/lib/protector/version.rb
+++ b/lib/protector/version.rb
@@ -1,4 +1,4 @@
 module Protector
   # Gem version
-  VERSION = "0.5.4"
+  VERSION = "0.5.5"
 end
diff --git a/migrations/active_record.rb b/migrations/active_record.rb
index 85d5a1d..0cae616 100644
--- a/migrations/active_record.rb
+++ b/migrations/active_record.rb
@@ -44,4 +44,7 @@ class Bobby < ActiveRecord::Base
 end
 
 class Loony < ActiveRecord::Base
+end
+
+class Rumba < ActiveRecord::Base
 end
\ No newline at end of file
diff --git a/migrations/sequel.rb b/migrations/sequel.rb
index a9df658..cf50ace 100644
--- a/migrations/sequel.rb
+++ b/migrations/sequel.rb
@@ -46,4 +46,7 @@ class Bobby < Sequel::Model
 end
 
 class Loony < Sequel::Model
+end
+
+class Rumba < Sequel::Model
 end
\ No newline at end of file
diff --git a/spec/lib/dsl_spec.rb b/spec/lib/dsl_spec.rb
index 2a0bc93..66015bd 100644
--- a/spec/lib/dsl_spec.rb
+++ b/spec/lib/dsl_spec.rb
@@ -42,7 +42,7 @@
         include Protector::DSL::Entry
 
         def self.protector_meta
-          @protector_meta ||= Protector::DSL::Meta.new nil, nil, []
+          @protector_meta ||= Protector::DSL::Meta.new(nil, nil){[]}
         end
       end
     end
@@ -61,7 +61,7 @@ def self.protector_meta
       l = lambda {|x| x > 4 }
 
       before :each do
-        @meta = Protector::DSL::Meta.new nil, nil, %w(field1 field2 field3 field4 field5)
+        @meta = Protector::DSL::Meta.new(nil, nil){%w(field1 field2 field3 field4 field5)}
         @meta << lambda {
           can :view
         }
@@ -159,7 +159,7 @@ def self.protector_meta
 
     context "custom methods" do
       before :each do
-        @meta = Protector::DSL::Meta.new nil, nil, %w(field1 field2)
+        @meta = Protector::DSL::Meta.new(nil, nil){%w(field1 field2)}
 
         @meta << lambda {
           can :drink, :field1
diff --git a/spec/spec_helpers/examples/model.rb b/spec/spec_helpers/examples/model.rb
index 9d786e0..4b873b8 100644
--- a/spec/spec_helpers/examples/model.rb
+++ b/spec/spec_helpers/examples/model.rb
@@ -30,6 +30,14 @@
     d.instance_variable_get('@protector_meta').should == nil
   end
 
+  it "doesn't get stuck with non-existing tables" do
+    Rumba.class_eval do
+      protect do
+        can
+      end
+    end
+  end
+
   describe "visibility" do
     it "marks blocked" do
       Dummy.first.restrict!('-').visible?.should == false