diff --git a/test/t/string.rb b/test/t/string.rb
index 3338e4318..27af38a4c 100644
--- a/test/t/string.rb
+++ b/test/t/string.rb
@@ -335,3 +335,7 @@ assert('String interpolation (mrb_str_concat for shared strings)') do
   "#{a}:" == "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA:"
 end
 
+assert('Check the usage of a NUL character') do
+  "qqq\0ppp"
+end
+