Integer is equals to numeric.

lib/simple_form/form_builder.rb

@@ -43,7 +43,7 @@ module SimpleForm
         column = @object.column_for_attribute(@attribute)
         input_type = column.type
         case input_type
-          when :decimal then :numeric
+          when :decimal, :integer then :numeric
           when :timestamp then :datetime
           when nil, :string then
             @attribute.to_s =~ /password/ ? :password : :string

lib/simple_form/input.rb

@@ -12,8 +12,6 @@ module SimpleForm
       :hidden   => Mapping.new(:hidden_field, false, false),
       :select   => Mapping.new(:collection_select, true, true),
       :radio    => Mapping.new(:collection_radio, true, false),
-      # Do we need integer and numeric?
-      :integer  => Mapping.new(:text_field, false, false),
       :numeric  => Mapping.new(:text_field, false, false),
       :string   => Mapping.new(:text_field, false, false)
     }

test/input_test.rb

@@ -42,7 +42,7 @@ class InputTest < ActionView::TestCase
     simple_form_for @user do |f|
       concat f.input :age
     end
-    assert_select 'form input.integer#user_age'
+    assert_select 'form input.numeric#user_age'
   end
 
   test 'input should generate a text field by default for decimal attributes' do

test/label_test.rb

@@ -73,7 +73,7 @@ class LabelTest < ActionView::TestCase
     assert_select 'form label.datetime[for=user_created_at]'
     assert_select 'form label.date[for=user_born_at]'
     assert_select 'form label.boolean[for=user_active]'
-    assert_select 'form label.integer[for=user_age]'
+    assert_select 'form label.numeric[for=user_age]'
     assert_select 'form label.numeric[for=user_credit_limit]'
   end