diff --git a/spec/codecs/json_lines_spec.rb b/spec/codecs/json_lines_spec.rb
index 3a87e06..1da1abb 100644
--- a/spec/codecs/json_lines_spec.rb
+++ b/spec/codecs/json_lines_spec.rb
@@ -130,7 +130,7 @@
       
       it "should raise an error if the max bytes are exceeded" do
         expect {
-          subject.decode(maximum_payload << "z")
+          subject.decode(maximum_payload + "z\n")
         }.to raise_error(java.lang.IllegalStateException, /input buffer full/)
       end
     end