1 files changed, 9 insertions, 9 deletions
diff --git a/spec/ruby/core/kernel/system_spec.rb b/spec/ruby/core/kernel/system_spec.rb
index 9bc03924dd..b24956104a 100644
--- a/spec/ruby/core/kernel/system_spec.rb
+++ b/spec/ruby/core/kernel/system_spec.rb
@@ -5,14 +5,14 @@ describe :kernel_system, shared: true do
   it "executes the specified command in a subprocess" do
     -> { @object.system("echo a") }.should output_to_fd("a\n")
 
-    $?.should be_an_instance_of Process::Status
+    $?.should.instance_of? Process::Status
     $?.should.success?
   end
 
   it "returns true when the command exits with a zero exit status" do
     @object.system(ruby_cmd('exit 0')).should == true
 
-    $?.should be_an_instance_of Process::Status
+    $?.should.instance_of? Process::Status
     $?.should.success?
     $?.exitstatus.should == 0
   end
@@ -20,24 +20,24 @@ describe :kernel_system, shared: true do
   it "returns false when the command exits with a non-zero exit status" do
     @object.system(ruby_cmd('exit 1')).should == false
 
-    $?.should be_an_instance_of Process::Status
+    $?.should.instance_of? Process::Status
     $?.should_not.success?
     $?.exitstatus.should == 1
   end
 
   it "raises RuntimeError when `exception: true` is given and the command exits with a non-zero exit status" do
-    -> { @object.system(ruby_cmd('exit 1'), exception: true) }.should raise_error(RuntimeError)
+    -> { @object.system(ruby_cmd('exit 1'), exception: true) }.should.raise(RuntimeError)
   end
 
   it "raises Errno::ENOENT when `exception: true` is given and the specified command does not exist" do
-    -> { @object.system('feature_14386', exception: true) }.should raise_error(Errno::ENOENT)
+    -> { @object.system('feature_14386', exception: true) }.should.raise(Errno::ENOENT)
   end
 
   it "returns nil when command execution fails" do
-    @object.system("sad").should be_nil
+    @object.system("sad").should == nil
 
-    $?.should be_an_instance_of Process::Status
-    $?.pid.should be_kind_of(Integer)
+    $?.should.instance_of? Process::Status
+    $?.pid.should.is_a?(Integer)
     $?.should_not.success?
   end
 
@@ -121,7 +121,7 @@ end
 
 describe "Kernel#system" do
   it "is a private method" do
-    Kernel.should have_private_instance_method(:system)
+    Kernel.private_instance_methods(false).should.include?(:system)
   end
 
   it_behaves_like :kernel_system, :system, KernelSpecs::Method.new