1 files changed, 2 insertions, 2 deletions
diff --git a/activerecord/test/cases/adapter_test.rb b/activerecord/test/cases/adapter_test.rb
index d7551cd658..9aaa2852d0 100644
--- a/activerecord/test/cases/adapter_test.rb
+++ b/activerecord/test/cases/adapter_test.rb
@@ -288,11 +288,11 @@ module ActiveRecord
       def test_log_invalid_encoding
         error = assert_raises RuntimeError do
           @connection.send :log, "SELECT 'ы' FROM DUAL" do
-            raise "ы".force_encoding(Encoding::ASCII_8BIT)
+            raise "ы".dup.force_encoding(Encoding::ASCII_8BIT)
           end
         end
 
-        assert_not_nil error.message
+        assert_equal "ы", error.message
       end
     end
   end