diff --git a/spec/ruby/core/time/fixtures/classes.rb b/spec/ruby/core/time/fixtures/classes.rb
index 328f9160f6..d89e4911c8 100644
--- a/spec/ruby/core/time/fixtures/classes.rb
+++ b/spec/ruby/core/time/fixtures/classes.rb
@@ -9,4 +9,18 @@ module TimeSpecs
     end
   end
 
+  Timezone = Struct.new(:name, :abbr, :offset)
+  class Timezone
+    def utc_offset(t = nil)
+      offset
+    end
+
+    def local_to_utc(t)
+      t - utc_offset(t)
+    end
+
+    def utc_to_local(t)
+      t + utc_offset(t)
+    end
+  end
 end
diff --git a/spec/ruby/core/time/new_spec.rb b/spec/ruby/core/time/new_spec.rb
index eced8a75fb..8d32c4e492 100644
--- a/spec/ruby/core/time/new_spec.rb
+++ b/spec/ruby/core/time/new_spec.rb
@@ -117,8 +117,7 @@ end
 ruby_version_is "2.6" do
   describe "Time.new with a timezone argument" do
     it "returns a Time correspoinding to UTC time returned by local_to_utc" do
-      zone = mock('timezone')
-      zone.should_receive(:local_to_utc).and_return(Time::TM.new(2000, 1, 1, 6, 30, 0))
+      zone = TimeSpecs::Timezone.new("Asia/Colombo", "MMT", (5*3600+30*60))
       t = Time.new(2000, 1, 1, 12, 0, 0, zone)
       t.to_a[0, 6].should == [0, 0, 12, 1, 1, 2000]
       t.utc_offset.should == 19800