1 files changed, 5 insertions, 4 deletions
diff --git a/spec/ruby/core/io/ungetbyte_spec.rb b/spec/ruby/core/io/ungetbyte_spec.rb
index 2e51fb0298..f5f9a11be1 100644
--- a/spec/ruby/core/io/ungetbyte_spec.rb
+++ b/spec/ruby/core/io/ungetbyte_spec.rb
@@ -49,7 +49,7 @@ describe "IO#ungetbyte" do
     end
   end
 
-  ruby_version_is '2.6'...'2.7' do
+  ruby_version_is '2.6'...'2.6.1' do
     it "is an RangeError if the integer is not in 8bit" do
       for i in [4095, 0x4f7574206f6620636861722072616e6765] do
         lambda { @io.ungetbyte(i) }.should raise_error(RangeError)
@@ -57,10 +57,11 @@ describe "IO#ungetbyte" do
     end
   end
 
-  ruby_version_is '2.7' do
+  ruby_version_is '2.6.1' do
     it "never raises RangeError" do
-      for i in [4095, 0x4f7574206f6620636861722072616e6765] do
-        lambda { @io.ungetbyte(i) }.should_not raise_error
+      for i in [4095, 0x4f7574206f6620636861722072616e67ff] do
+        @io.ungetbyte(i).should be_nil
+        @io.getbyte.should == 255
       end
     end
   end