diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index a10a5069ac..4c0625b8db 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,13 @@
 *SVN*
 
+* Change belongs_to so that the foreign_key assumption is taken from the association name, not the class name.  Closes #8992 [hasmanyjosh]
+
+  OLD
+    belongs_to :visitor, :class_name => 'User' # => inferred foreign_key is user_id
+    
+  NEW
+    belongs_to :visitor, :class_name => 'User' # => inferred foreign_key is visitor_id
+
 * Remove spurious tests from deprecated_associations_test, most of these aren't deprecated, and are duplicated in associations_test.  Closes #8987 [lifofifo]
 
 * Make create! on a has_many :through association return the association object.  Not the collection.  Closes #8786 [lifofifo]
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index ca739eb5dc..b9839a8500 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -799,12 +799,6 @@ module ActiveRecord
       #              :conditions => 'discounts > #{payments_count}'
       #   belongs_to :attachable, :polymorphic => true
       def belongs_to(association_id, options = {})
-        if options.include?(:class_name) && !options.include?(:foreign_key)
-          ::ActiveSupport::Deprecation.warn(
-          "The inferred foreign_key name will change in Rails 2.0 to use the association name instead of its class name when they differ.  When using :class_name in belongs_to, use the :foreign_key option to explicitly set the key name to avoid problems in the transition.",
-          caller)
-        end
-        
         reflection = create_belongs_to_reflection(association_id, options)
         
         if reflection.options[:polymorphic]
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 62184eeff2..3d76ffe776 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -207,7 +207,7 @@ module ActiveRecord
 
         def derive_primary_key_name
           if macro == :belongs_to
-            class_name.foreign_key
+            "#{name}_id"
           elsif options[:as]
             "#{options[:as]}_id"
           else
diff --git a/activerecord/test/associations_test.rb b/activerecord/test/associations_test.rb
index bf6d8301a2..0db8d91099 100755
--- a/activerecord/test/associations_test.rb
+++ b/activerecord/test/associations_test.rb
@@ -409,13 +409,6 @@ class HasOneAssociationsTest < Test::Unit::TestCase
     end
   end
 
-  def test_deprecated_inferred_foreign_key
-    assert_not_deprecated { Company.belongs_to :firm }
-    assert_not_deprecated { Company.belongs_to :client, :foreign_key => "firm_id" }
-    assert_not_deprecated { Company.belongs_to :firm, :class_name => "Firm", :foreign_key => "client_of" }
-    assert_deprecated("inferred foreign_key name") { Company.belongs_to :client, :class_name => "Firm" }
-  end
-
 end
 
 
diff --git a/activerecord/test/reflection_test.rb b/activerecord/test/reflection_test.rb
index cc06d31299..1ed5c2610c 100644
--- a/activerecord/test/reflection_test.rb
+++ b/activerecord/test/reflection_test.rb
@@ -111,6 +111,15 @@ class ReflectionTest < Test::Unit::TestCase
     assert_equal 'accounts', Firm.reflect_on_association(:account).table_name
   end
 
+  def test_belongs_to_inferred_foreign_key_from_assoc_name
+    Company.belongs_to :foo
+    assert_equal "foo_id", Company.reflect_on_association(:foo).primary_key_name
+    Company.belongs_to :bar, :class_name => "Xyzzy"
+    assert_equal "bar_id", Company.reflect_on_association(:bar).primary_key_name
+    Company.belongs_to :baz, :class_name => "Xyzzy", :foreign_key => "xyzzy_id"
+    assert_equal "xyzzy_id", Company.reflect_on_association(:baz).primary_key_name
+  end
+
   def test_association_reflection_in_modules
     assert_reflection MyApplication::Business::Firm,
       :clients_of_firm,