diff --git a/test/unit/os/shell_spec.lua b/test/unit/os/shell_spec.lua
index 91123bfd58..20cfc17950 100644
--- a/test/unit/os/shell_spec.lua
+++ b/test/unit/os/shell_spec.lua
@@ -68,5 +68,10 @@ describe('shell functions', function()
       eq(input, output)
       eq(0, status)
     end)
+
+    it ('returns non-zero exit code', function()
+      local status, output = os_system('exit 2')
+      eq(2, status)
+    end)
   end)
 end)