1 files changed, 13 insertions, 9 deletions
diff --git a/spec/ruby/library/stringio/external_encoding_spec.rb b/spec/ruby/library/stringio/external_encoding_spec.rb
index 1a57081287..6c5edb1713 100644
--- a/spec/ruby/library/stringio/external_encoding_spec.rb
+++ b/spec/ruby/library/stringio/external_encoding_spec.rb
@@ -8,14 +8,18 @@ describe "StringIO#external_encoding" do
     io.external_encoding.should == Encoding::EUC_JP
   end
 
-  ruby_version_is "2.3" do
-    it "does not set the encoding of its buffer string if the string is frozen" do
-      str = "foo".freeze
-      enc = str.encoding
-      io = StringIO.new(str)
-      io.set_encoding Encoding::EUC_JP
-      io.external_encoding.should == Encoding::EUC_JP
-      str.encoding.should == enc
-    end
+  it "changes to match string if string's encoding is changed" do
+    io = StringIO.new
+    io.string.force_encoding(Encoding::EUC_JP)
+    io.external_encoding.should == Encoding::EUC_JP
+  end
+
+  it "does not set the encoding of its buffer string if the string is frozen" do
+    str = "foo".freeze
+    enc = str.encoding
+    io = StringIO.new(str)
+    io.set_encoding Encoding::EUC_JP
+    io.external_encoding.should == Encoding::EUC_JP
+    str.encoding.should == enc
   end
 end