1 files changed, 12 insertions, 14 deletions
diff --git a/spec/ruby/core/time/shared/now.rb b/spec/ruby/core/time/shared/now.rb
index d8e5ac9d50..839cfdcd2a 100644
--- a/spec/ruby/core/time/shared/now.rb
+++ b/spec/ruby/core/time/shared/now.rb
@@ -2,8 +2,8 @@ require_relative '../fixtures/classes'
 
 describe :time_now, shared: true do
   it "creates a subclass instance if called on a subclass" do
-    TimeSpecs::SubTime.send(@method).should be_an_instance_of(TimeSpecs::SubTime)
-    TimeSpecs::MethodHolder.send(@method).should be_an_instance_of(Time)
+    TimeSpecs::SubTime.send(@method).should.instance_of?(TimeSpecs::SubTime)
+    TimeSpecs::MethodHolder.send(@method).should.instance_of?(Time)
   end
 
   it "sets the current time" do
@@ -18,18 +18,16 @@ describe :time_now, shared: true do
     end
   end
 
-  guard_not -> { platform_is :windows and ruby_version_is ""..."2.5" } do
-    it "has at least microsecond precision" do
-      times = []
-      10_000.times do
-        times << Time.now.nsec
-      end
-
-      # The clock should not be less accurate than expected (times should
-      # not all be a multiple of the next precision up, assuming precisions
-      # are multiples of ten.)
-      expected = 1_000
-      times.select { |t| t % (expected * 10) == 0  }.size.should_not == times.size
+  it "has at least microsecond precision" do
+    # The clock should not be less accurate than expected (times should
+    # not all be a multiple of the next precision up, assuming precisions
+    # are multiples of ten.)
+    expected = 1_000
+    t = 0
+    10_000.times.find do
+      t = Time.now.nsec
+      t % (expected * 10) != 0
     end
+    (t % (expected * 10)).should != 0
   end
 end