diff --git a/spec/helper.rb b/spec/helper.rb
index <HASH>..<HASH> 100644
--- a/spec/helper.rb
+++ b/spec/helper.rb
@@ -25,10 +25,6 @@ class TimeWithZone
   end
 end
 
-def nsjsonserialization_on_other_than_macruby(engine)
-  engine == 'nsjsonserialization' && !macruby?
-end
-
 def jruby?
   defined?(RUBY_ENGINE) && RUBY_ENGINE == 'jruby'
 end
diff --git a/spec/multi_json_spec.rb b/spec/multi_json_spec.rb
index <HASH>..<HASH> 100644
--- a/spec/multi_json_spec.rb
+++ b/spec/multi_json_spec.rb
@@ -61,10 +61,8 @@ describe "MultiJson" do
   end
 
   %w(json_gem json_pure nsjsonserialization oj ok_json yajl).each do |engine|
-    if nsjsonserialization_on_other_than_macruby(engine)
-      puts "NSJSONSerialization is exclusively available for MacRuby only."
-      next
-    end
+    next if !macruby? && engine == 'nsjsonserialization'
+    next if jruby? && engine == 'oj'
 
     context engine do
       before do
Don't test Oj on JRuby