diff --git a/lib/truffle/stringio.rb b/lib/truffle/stringio.rb
index 8e7c64d87526..1f2465af94b7 100644
--- a/lib/truffle/stringio.rb
+++ b/lib/truffle/stringio.rb
@@ -100,7 +100,7 @@ def puts(*args)
     Truffle::IOOperations.puts(self, *args)
   end
 
-  def write_nonblock(str)
+  def write_nonblock(str, exception: true)
     write(str)
   end
 
diff --git a/spec/ruby/library/stringio/read_nonblock_spec.rb b/spec/ruby/library/stringio/read_nonblock_spec.rb
index 2a8f926bd064..d4ec56d9aada 100644
--- a/spec/ruby/library/stringio/read_nonblock_spec.rb
+++ b/spec/ruby/library/stringio/read_nonblock_spec.rb
@@ -5,10 +5,21 @@
 
 describe "StringIO#read_nonblock when passed length, buffer" do
   it_behaves_like :stringio_read, :read_nonblock
+
+  it "accepts :exception option" do
+    io = StringIO.new("example")
+    io.read_nonblock(3, buffer = "", exception: true)
+    buffer.should == "exa"
+  end
 end
 
 describe "StringIO#read_nonblock when passed length" do
   it_behaves_like :stringio_read_length, :read_nonblock
+
+  it "accepts :exception option" do
+    io = StringIO.new("example")
+    io.read_nonblock(3, exception: true).should == "exa"
+  end
 end
 
 describe "StringIO#read_nonblock when passed nil" do
diff --git a/spec/ruby/library/stringio/write_nonblock_spec.rb b/spec/ruby/library/stringio/write_nonblock_spec.rb
index 4f4c5039fe24..a457b976679e 100644
--- a/spec/ruby/library/stringio/write_nonblock_spec.rb
+++ b/spec/ruby/library/stringio/write_nonblock_spec.rb
@@ -8,6 +8,12 @@
 
 describe "StringIO#write_nonblock when passed [String]" do
   it_behaves_like :stringio_write_string, :write_nonblock
+
+  it "accepts :exception option" do
+    io = StringIO.new("12345", "a")
+    io.write_nonblock("67890", exception: true)
+    io.string.should == "1234567890"
+  end
 end
 
 describe "StringIO#write_nonblock when self is not writable" do