1 files changed, 4 insertions, 4 deletions
diff --git a/spec/ruby/core/fiber/new_spec.rb b/spec/ruby/core/fiber/new_spec.rb
index b43c1386be..d31167496d 100644
--- a/spec/ruby/core/fiber/new_spec.rb
+++ b/spec/ruby/core/fiber/new_spec.rb
@@ -4,7 +4,7 @@ describe "Fiber.new" do
   it "creates a fiber from the given block" do
     fiber = Fiber.new {}
     fiber.resume
-    fiber.should be_an_instance_of(Fiber)
+    fiber.should.instance_of?(Fiber)
   end
 
   it "creates a fiber from a subclass" do
@@ -12,17 +12,17 @@ describe "Fiber.new" do
     end
     fiber = MyFiber.new {}
     fiber.resume
-    fiber.should be_an_instance_of(MyFiber)
+    fiber.should.instance_of?(MyFiber)
   end
 
   it "raises an ArgumentError if called without a block" do
-    -> { Fiber.new }.should raise_error(ArgumentError)
+    -> { Fiber.new }.should.raise(ArgumentError)
   end
 
   it "does not invoke the block" do
     invoked = false
     fiber = Fiber.new { invoked = true }
-    invoked.should be_false
+    invoked.should == false
     fiber.resume
   end