1 files changed, 10 insertions, 2 deletions
diff --git a/activemodel/lib/active_model/type/decimal.rb b/activemodel/lib/active_model/type/decimal.rb
index d19d8baada..11ea327026 100644
--- a/activemodel/lib/active_model/type/decimal.rb
+++ b/activemodel/lib/active_model/type/decimal.rb
@@ -29,12 +29,12 @@ module ActiveModel
           end
         end
 
-        scale ? casted_value.round(scale) : casted_value
+        apply_scale(casted_value)
       end
 
       def convert_float_to_big_decimal(value)
         if precision
-          BigDecimal(value, float_precision)
+          BigDecimal(apply_scale(value), float_precision)
         else
           value.to_d
         end
@@ -47,6 +47,14 @@ module ActiveModel
           precision.to_i
         end
       end
+
+      def apply_scale(value)
+        if scale
+          value.round(scale)
+        else
+          value
+        end
+      end
     end
   end
 end