diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index de530a345663e..2d90ef35aaad0 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -99,8 +99,15 @@ def table(table, stream)
             next if column.name == pk
             spec = {}
             spec[:name]      = column.name.inspect
-            spec[:type]      = column.type.to_s
-            spec[:limit]     = column.limit.inspect if column.limit != @types[column.type][:limit] && column.type != :decimal
+            
+            # AR has an optimisation which handles zero-scale decimals as integers.  This
+            # code ensures that the dumper still dumps the column as a decimal.
+            spec[:type]      = if column.type == :integer && [/^numeric/, /^decimal/].any? { |e| e.match(column.sql_type) }
+                                 'decimal'
+                               else
+                                 column.type.to_s
+                               end
+            spec[:limit]     = column.limit.inspect if column.limit != @types[column.type][:limit] && spec[:type] != 'decimal'
             spec[:precision] = column.precision.inspect if !column.precision.nil?
             spec[:scale]     = column.scale.inspect if !column.scale.nil?
             spec[:null]      = 'false' if !column.null
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index f9ad7f3ba3c7f..4f02be3c06e30 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -190,4 +190,9 @@ def test_schema_dump_includes_decimal_options
     output = stream.string
     assert_match %r{:precision => 3,[[:space:]]+:scale => 2,[[:space:]]+:default => 2.78}, output
   end
+
+  def test_schema_dump_keeps_large_precision_integer_columns_as_decimal
+    output = standard_dump
+    assert_match %r{t.decimal\s+"atoms_in_universe",\s+:precision => 55,\s+:scale => 0}, output
+  end
 end
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 6e8813d8ab9ba..b2aaccb35206b 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -273,6 +273,7 @@ def create_table(*args, &block)
     t.decimal :my_house_population, :precision => 2, :scale => 0
     t.decimal :decimal_number_with_default, :precision => 3, :scale => 2, :default => 2.78
     t.float   :temperature
+    t.decimal :atoms_in_universe, :precision => 55, :scale => 0
   end
 
   create_table :orders, :force => true do |t|