2 files changed, 16 insertions, 8 deletions
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index c5997283ea..9cb8b543b0 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -10,7 +10,6 @@ module ActiveModel
       RESERVED_OPTIONS = CHECKS.keys + [:only_integer]
 
       INTEGER_REGEX = /\A[+-]?\d+\z/
-      DECIMAL_REGEX = /\A[+-]?\d+\.?\d*(e|e[+-])?\d+\z/
 
       def check_validity!
         keys = CHECKS.keys - [:odd, :even]
@@ -92,8 +91,8 @@ module ActiveModel
           raw_value
         elsif is_integer?(raw_value)
           raw_value.to_i
-        elsif is_decimal?(raw_value) && !is_hexadecimal_literal?(raw_value)
-          BigDecimal(raw_value)
+        elsif !is_hexadecimal_literal?(raw_value)
+          Kernel.Float(raw_value).to_d
         end
       end
 
@@ -101,12 +100,8 @@ module ActiveModel
         INTEGER_REGEX.match?(raw_value.to_s)
       end
 
-      def is_decimal?(raw_value)
-        DECIMAL_REGEX.match?(raw_value.to_s)
-      end
-
       def is_hexadecimal_literal?(raw_value)
-        /\A0[xX]/.match?(raw_value)
+        /\A0[xX]/.match?(raw_value.to_s)
       end
 
       def filtered_options(value)
diff --git a/activemodel/test/cases/validations/numericality_validation_test.rb b/activemodel/test/cases/validations/numericality_validation_test.rb
index eb4b02df93..fcdf123062 100644
--- a/activemodel/test/cases/validations/numericality_validation_test.rb
+++ b/activemodel/test/cases/validations/numericality_validation_test.rb
@@ -281,6 +281,19 @@ class NumericalityValidationTest < ActiveModel::TestCase
     assert_predicate topic, :invalid?
   end
 
+  def test_validates_numericalty_with_object_acting_as_numeric
+    klass = Class.new do
+      def to_f
+        123.54
+      end
+    end
+
+    Topic.validates_numericality_of :price
+    topic = Topic.new(price: klass.new)
+
+    assert_predicate topic, :valid?
+  end
+
   def test_validates_numericality_with_invalid_args
     assert_raise(ArgumentError) { Topic.validates_numericality_of :approved, greater_than_or_equal_to: "foo" }
     assert_raise(ArgumentError) { Topic.validates_numericality_of :approved, less_than_or_equal_to: "foo" }