diff --git a/ruby/tests/encode_decode_test.rb b/ruby/tests/encode_decode_test.rb
index f8b991c..d2b25fd 100644
--- a/ruby/tests/encode_decode_test.rb
+++ b/ruby/tests/encode_decode_test.rb
@@ -86,7 +86,7 @@
   end
 
   def test_encode_wrong_msg
-    e = assert_raise ::ArgumentError do
+    assert_raise ::ArgumentError do
       m = A::B::C::TestMessage.new(
           :optional_int32 => 1,
       )