2 files changed, 25 insertions, 16 deletions
diff --git a/activesupport/lib/active_support/core_ext/big_decimal/conversions.rb b/activesupport/lib/active_support/core_ext/big_decimal/conversions.rb
index 843c592669..234283e792 100644
--- a/activesupport/lib/active_support/core_ext/big_decimal/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/big_decimal/conversions.rb
@@ -3,14 +3,13 @@ require 'bigdecimal/util'
 
 class BigDecimal
   DEFAULT_STRING_FORMAT = 'F'
-  def to_formatted_s(*args)
-    if args[0].is_a?(Symbol)
-      super
+  alias_method :to_default_s, :to_s
+
+  def to_s(format = nil, options = nil)
+    if format.is_a?(Symbol)
+      to_formatted_s(format, options || {})
     else
-      format = args[0] || DEFAULT_STRING_FORMAT
-      _original_to_s(format)
+      to_default_s(format || DEFAULT_STRING_FORMAT)
     end
   end
-  alias_method :_original_to_s, :to_s
-  alias_method :to_s, :to_formatted_s
 end
diff --git a/activesupport/lib/active_support/core_ext/numeric/conversions.rb b/activesupport/lib/active_support/core_ext/numeric/conversions.rb
index 6d3635c69a..0c8ff79237 100644
--- a/activesupport/lib/active_support/core_ext/numeric/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/numeric/conversions.rb
@@ -118,18 +118,28 @@ class Numeric
     end
   end
 
-  [Float, Fixnum, Bignum, BigDecimal].each do |klass|
-    klass.send(:alias_method, :to_default_s, :to_s)
-
-    klass.send(:define_method, :to_s) do |*args|
-      if args[0].is_a?(Symbol)
-        format = args[0]
-        options = args[1] || {}
+  [Fixnum, Bignum].each do |klass|
+    klass.class_eval do
+      alias_method :to_default_s, :to_s
+      def to_s(base_or_format = 10, options = nil)
+        if base_or_format.is_a?(Symbol)
+          to_formatted_s(base_or_format, options || {})
+        else
+          to_default_s(base_or_format)
+        end
+      end
+    end
+  end
 
-        self.to_formatted_s(format, options)
+  Float.class_eval do
+    alias_method :to_default_s, :to_s
+    def to_s(*args)
+      if args.empty?
+        to_default_s
       else
-        to_default_s(*args)
+        to_formatted_s(*args)
       end
     end
   end
+
 end