1 files changed, 3 insertions, 3 deletions
diff --git a/spec/ruby/library/stringio/read_nonblock_spec.rb b/spec/ruby/library/stringio/read_nonblock_spec.rb
index d4ec56d9aa..38ae7541ca 100644
--- a/spec/ruby/library/stringio/read_nonblock_spec.rb
+++ b/spec/ruby/library/stringio/read_nonblock_spec.rb
@@ -8,7 +8,7 @@ describe "StringIO#read_nonblock when passed length, buffer" do
 
   it "accepts :exception option" do
     io = StringIO.new("example")
-    io.read_nonblock(3, buffer = "", exception: true)
+    io.read_nonblock(3, buffer = +"", exception: true)
     buffer.should == "exa"
   end
 end
@@ -40,12 +40,12 @@ describe "StringIO#read_nonblock" do
   context "when exception option is set to false" do
     context "when the end is reached" do
       it "returns nil" do
-        stringio = StringIO.new('')
+        stringio = StringIO.new(+'')
         stringio << "hello"
         stringio.rewind
 
         stringio.read_nonblock(5).should == "hello"
-        stringio.read_nonblock(5, exception: false).should be_nil
+        stringio.read_nonblock(5, exception: false).should == nil
       end
     end
   end