diff --git a/process.c b/process.c
index 7a4fa3066e..0195a0fe23 100644
--- a/process.c
+++ b/process.c
@@ -2210,7 +2210,9 @@ rb_exec_fillarg(VALUE prog, int argc, VALUE *argv, VALUE env, VALUE opthash, VAL
                 }
             }
             eargp->invoke.cmd.argv_buf = argv_buf;
-            eargp->invoke.cmd.command_name = hide_obj(rb_str_new_cstr(RSTRING_PTR(argv_buf)));
+            eargp->invoke.cmd.command_name =
+                hide_obj(rb_str_subseq(argv_buf, 0, strlen(RSTRING_PTR(argv_buf))));
+            rb_enc_copy(eargp->invoke.cmd.command_name, prog);
         }
     }
 #endif
diff --git a/test/ruby/test_system.rb b/test/ruby/test_system.rb
index c56e2a13c4..edc70a4496 100644
--- a/test/ruby/test_system.rb
+++ b/test/ruby/test_system.rb
@@ -181,5 +181,21 @@ class TestSystem < Test::Unit::TestCase
     assert_raise_with_message(RuntimeError, /\ACommand failed with exit /) do
       system("'#{ruby}' -e abort", exception: true)
     end
+
+    Dir.mktmpdir("ruby_script_tmp") do |tmpdir|
+      name = "\u{30c6 30b9 30c8}"
+      tmpfilename = "#{tmpdir}/#{name}.cmd"
+      message = /#{name}\.cmd/
+      e = assert_raise_with_message(Errno::ENOENT, message) do
+        system(tmpfilename, exception: true)
+      end
+      open(tmpfilename, "w") {|f|
+        f.puts "exit 127"
+        f.chmod(0755)
+      }
+      e = assert_raise_with_message(RuntimeError, message) do
+        system(tmpfilename, exception: true)
+      end
+    end
   end
 end