diff --git a/lib/squash/ruby.rb b/lib/squash/ruby.rb
index 8ad9193..1fcbf10 100644
--- a/lib/squash/ruby.rb
+++ b/lib/squash/ruby.rb
@@ -47,8 +47,15 @@ module Ruby
     }
     # Types that are serialized directly to JSON, rather than to a hash of
     # object information. Subclasses are not considered members of this array.
-    JSON_NATIVE_TYPES        = [String, NilClass, TrueClass, FalseClass, Integer,
-                                Fixnum, Float]
+    if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('2.4.0')
+      JSON_NATIVE_TYPES = [
+        String, NilClass, TrueClass, FalseClass, Fixnum, Float
+      ].freeze
+    else
+      JSON_NATIVE_TYPES = [
+        String, NilClass, TrueClass, FalseClass, Integer, Fixnum, Float
+      ].freeze
+    end
     # Array of user-data fields that should be moved out of the user data to
     # become top-level attributes. A Rails client library would expand this
     # constant to include Rails-specific fields, for example.
diff --git a/squash_ruby.gemspec b/squash_ruby.gemspec
index e11be8c..d74360d 100644
--- a/squash_ruby.gemspec
+++ b/squash_ruby.gemspec
@@ -6,7 +6,7 @@
 
 Gem::Specification.new do |s|
   s.name = "squash_ruby".freeze
-  s.version = "2.0.1"
+  s.version = "2.0.2"
 
   s.required_rubygems_version = Gem::Requirement.new(">= 0".freeze) if s.respond_to? :required_rubygems_version=
   s.require_paths = ["lib".freeze]