diff --git a/spec/timeliness/parser_spec.rb b/spec/timeliness/parser_spec.rb
index <HASH>..<HASH> 100644
--- a/spec/timeliness/parser_spec.rb
+++ b/spec/timeliness/parser_spec.rb
@@ -64,6 +64,18 @@ describe Timeliness::Parser do
       should_not_parse("2000-02-01 25:13:14")
     end
 
+    describe "threadsafety" do
+      it "should allow thread with own format" do
+        eu_date = "30/06/2016"
+        us_date = "06/30/2016"
+        threads = []
+        threads << Thread.new { Timeliness.use_euro_formats; sleep(0.005); Timeliness.parse(eu_date) }
+        threads << Thread.new { sleep(0.001); Timeliness.use_us_formats; Timeliness.parse(us_date) }
+        threads.each { |t| t.join }
+        threads.each { |t| expect(t.value).to eql(Time.new(2016,06,30)) }
+      end
+    end
+
     context "string with zone offset value" do
       context "when current timezone is earler than string zone" do
         before(:all) do
Spec to test threadsafety