diff --git a/spec/md5_spec.lua b/spec/md5_spec.lua
index 8425c95..69dde39 100644
--- a/spec/md5_spec.lua
+++ b/spec/md5_spec.lua
@@ -16,6 +16,10 @@ describe('md5', function()
       assert.equal(md5.sumhexa(''), 'd41d8cd98f00b204e9800998ecf8427e')
       assert.equal(md5.sumhexa(('1'):rep(824)), 'a126fd3611ab8d9b7e8a3384e2fa78a0')
       assert.equal(md5.sumhexa(('1'):rep(1528)), '3750b6a29d923b633e05d6ae76895664')
+      local state = md5.new()
+      state:update('Hello')
+      state:update(', World!')
+      assert.equal(md5.tohex(state:finish()), '65a8e27d8879283831b664bd8b7f0ad4')
     end)
   end)
 
@@ -27,6 +31,10 @@ describe('md5', function()
       assert.equal(md5.sum(''), hex2bin 'd41d8cd98f00b204e9800998ecf8427e')
       assert.equal(md5.sum(('1'):rep(824)), hex2bin 'a126fd3611ab8d9b7e8a3384e2fa78a0')
       assert.equal(md5.sum(('1'):rep(1528)), hex2bin '3750b6a29d923b633e05d6ae76895664')
+      local state = md5.new()
+      state:update('Hello')
+      state:update(', World!')
+      assert.equal(state:finish(), hex2bin '65a8e27d8879283831b664bd8b7f0ad4')
     end)
   end)
 end)