diff --git a/spec/formatters_spec.lua b/spec/formatters_spec.lua
index d91b2c4..3ac5962 100644
--- a/spec/formatters_spec.lua
+++ b/spec/formatters_spec.lua
@@ -17,7 +17,7 @@ describe("Test Formatters", function()
   after_each(function()
     snapshot:revert()
   end)
-  
+
   it("Checks to see if types are returned as strings", function()
     assert.is.same(assert:format({ "a string", ["n"] = 1 })[1], "(string) 'a string'")
     assert.is.same(assert:format({ true, ["n"] = 1 })[1], "(boolean) true")
@@ -37,38 +37,47 @@ describe("Test Formatters", function()
   end)
 
   it("Checks to see if tables are recursively serialized", function()
-    assert.is.same(assert:format({ {}, ["n"] = 1 })[1], "(table) { }")
-    assert.is.same(assert:format({ { 2, 3, 4, [-5] = 7}, ["n"] = 1 })[1], [[(table) {
+    local t = {}
+    assert.is.same(assert:format({ t, ["n"] = 1 })[1], "("..tostring(t)..") { }")
+    t = { 2, 3, 4, [-5] = 7}
+    assert.is.same(assert:format({ t, ["n"] = 1 })[1], [[(]]..tostring(t)..[[) {
   [1] = 2
   [2] = 3
   [3] = 4
   [-5] = 7 }]])
-    assert.is.same(assert:format({ { 1, ["k1"] = "v1", ["k2"] = "v2"}, ["n"] = 1 })[1], [[(table) {
+    t = { 1, ["k1"] = "v1", ["k2"] = "v2"}
+    assert.is.same(assert:format({ t, ["n"] = 1 })[1], [[(]]..tostring(t)..[[) {
   [1] = 1
   [k1] = 'v1'
   [k2] = 'v2' }]])
-    assert.is.same(assert:format({ { "{\n }\n" }, ["n"] = 1 })[1], [[(table) {
+    t = { "{\n }\n" }
+    assert.is.same(assert:format({ t, ["n"] = 1 })[1], [[(]]..tostring(t)..[[) {
   [1] = '{
  }
 ' }]])
   end)
 
   it("Checks to see if TableFormatLevel parameter limits table formatting depth", function()
-    assert.is.same(assert:format({ { { { { 1 } } } }, ["n"] = 1 })[1], [[(table) {
+    local t = { { { { 1 } } } }
+    assert.is.same(assert:format({ t, ["n"] = 1 })[1], [[(]]..tostring(t)..[[) {
   [1] = {
     [1] = {
       [1] = { ... more } } } }]])
-    assert.is.same(assert:format({ { { { } } }, ["n"] = 1 })[1], [[(table) {
+    t = { { { } } }
+    assert.is.same(assert:format({ t, ["n"] = 1 })[1], [[(]]..tostring(t)..[[) {
   [1] = {
     [1] = { } } }]])
     assert:set_parameter("TableFormatLevel", 0)
-    assert.is.same(assert:format({ { }, ["n"] = 1 })[1], "(table) { }")
-    assert.is.same(assert:format({ { 1 }, ["n"] = 1 })[1], "(table) { ... more }")
+    t = { }
+    assert.is.same(assert:format({ t, ["n"] = 1 })[1], "("..tostring(t)..") { }")
+    t = { 1 }
+    assert.is.same(assert:format({ t, ["n"] = 1 })[1], "("..tostring(t)..") { ... more }")
   end)
 
   it("Checks to see if TableFormatLevel parameter can display all levels", function()
     assert:set_parameter("TableFormatLevel", -1)
-    assert.is.same(assert:format({ { { { { 1 } } } }, ["n"] = 1 })[1], [[(table) {
+    local t = { { { { 1 } } } }
+    assert.is.same(assert:format({ t, ["n"] = 1 })[1], [[(]]..tostring(t)..[[) {
   [1] = {
     [1] = {
       [1] = {
@@ -80,7 +89,7 @@ describe("Test Formatters", function()
     local t = {{1,2},{3,4}}
     local fmtargs = { {crumbs = {1,2}} }
     local formatted = assert:format({t, n = 1, fmtargs = fmtargs})[1]
-    local expected = "(table) {\n  [1] = {\n    [1] = 1\n    [2] = 2 }\n *[2] = {\n   *[1] = 3\n    [2] = 4 } }"
+    local expected = "("..tostring(t)..") {\n  [1] = {\n    [1] = 1\n    [2] = 2 }\n *[2] = {\n   *[1] = 3\n    [2] = 4 } }"
     assert.is.equal(expected, formatted)
   end)
 
@@ -89,7 +98,7 @@ describe("Test Formatters", function()
     local t = {1,2,3}
     local fmtargs = { {crumbs = {2}} }
     local formatted = assert:format({t, n = 1, fmtargs = fmtargs})[1]
-    local expected = "(table) {\n  [1] = 1\n**[2] = 2\n  [3] = 3 }"
+    local expected = "("..tostring(t)..") {\n  [1] = 1\n**[2] = 2\n  [3] = 3 }"
     assert.is.equal(expected, formatted)
   end)
 
@@ -101,7 +110,7 @@ describe("Test Formatters", function()
     local t = {1,2,3}
     local fmtargs = { {crumbs = {2}} }
     local formatted = assert:format({t, n = 1, fmtargs = fmtargs})[1]
-    local expected = string.format("(table) {\n  [1] = 1\n %s[2] = 2\n  [3] = 3 }", colors.red("*"))
+    local expected = string.format("("..tostring(t)..") {\n  [1] = 1\n %s[2] = 2\n  [3] = 3 }", colors.red("*"))
     assert.is.equal(expected, formatted)
   end)
 
@@ -110,7 +119,7 @@ describe("Test Formatters", function()
     t[3] = t
     assert:set_parameter("TableFormatShowRecursion", true)
     local formatted = assert:format({t, n = 1})[1]
-    local expected = "(table) {\n  [1] = 1\n  [2] = 2\n  [3] = { ... recursive } }"
+    local expected = "("..tostring(t)..") {\n  [1] = 1\n  [2] = 2\n  [3] = { ... recursive } }"
     assert.is.equal(expected, formatted)
   end)
 
@@ -137,7 +146,7 @@ describe("Test Formatters", function()
     assert.is.same(type(formatted[3]), "string")
     assert.is.same(type(formatted[4]), "nil")
   end)
-  
+
   it("checks arguments not being formatted if set to do so", function()
     local arg1 = "argument1"
     local arg2 = "argument2"
@@ -146,7 +155,7 @@ describe("Test Formatters", function()
     arguments = assert:format(arguments)
     assert.is.same(arg1, arguments[1])
   end)
-  
+
   it("checks extra formatters inserted to be called first", function()
     local expected = "formatted result"
     local f = function(value)
@@ -155,11 +164,11 @@ describe("Test Formatters", function()
       end
     end
     local s = spy.new(f)
-    
+
     assert:add_formatter(s)
     assert.are_equal(expected, assert:format({"some string"})[1])
     assert.spy(s).was.called(1)
     assert:remove_formatter(s)
   end)
-  
+
 end)
diff --git a/spec/output_spec.lua b/spec/output_spec.lua
index 7313176..57a72a5 100644
--- a/spec/output_spec.lua
+++ b/spec/output_spec.lua
@@ -72,8 +72,9 @@ describe("Output testing using string comparison with the has_error assertion",
 
   it("Should compare error strings correctly; table-string", function()
     --assert.has_error(function() error({}) end, "string")
-    local output = getoutput(function() error({}) end, "string")
-    local ok = output:find("Caught:\n%(table%) { }")
+    local t = {}
+    local output = getoutput(function() error(t) end, "string")
+    local ok = output:find("Caught:\n%("..tostring(t).."%) { }")
     assert(ok, "Output check 1 failed, comparing table-string;\n    " .. output:gsub("\n","\n    "))
     local ok = output:find("Expected:\n%(string%) 'string'")
     assert(ok, "Output check 2 failed, comparing table-string;\n    " .. output:gsub("\n","\n    "))
@@ -81,19 +82,22 @@ describe("Output testing using string comparison with the has_error assertion",
 
   it("Should compare error strings correctly; string-table", function()
     --assert.has_error(function() error("string") end, {})
-    local output = getoutput(function() error("string") end, {})
+    local t = {}
+    local output = getoutput(function() error("string") end, t)
     local ok = output:find("Caught:\n%(string%) 'string'")
     assert(ok, "Output check 1 failed, comparing string-table;\n    " .. output:gsub("\n","\n    "))
-    local ok = output:find("Expected:\n%(table%) { }")
+    local ok = output:find("Expected:\n%("..tostring(t).."%) { }")
     assert(ok, "Output check 2 failed, comparing string-table;\n    " .. output:gsub("\n","\n    "))
   end)
 
   it("Should compare error objects correctly; table-table", function()
     --assert.has_error(function() error({}) end, { "table" })
-    local output = getoutput(function() error({}) end, { "table" })
-    local ok = output:find("Caught:\n%(table%) { }")
+    local t = {}
+    local t2 = { "table" }
+    local output = getoutput(function() error(t) end, t2)
+    local ok = output:find("Caught:\n%("..tostring(t).."%) { }")
     assert(ok, "Output check 1 failed, comparing table-table;\n    " .. output:gsub("\n","\n    "))
-    local ok = output:find("Expected:\n%(table%) {\n  %[1] = 'table' }")
+    local ok = output:find("Expected:\n%("..tostring(t2).."%) {\n  %[1] = 'table' }")
     assert(ok, "Output check 2 failed, comparing table-table;\n    " .. output:gsub("\n","\n    "))
   end)
 
@@ -108,10 +112,11 @@ describe("Output testing using string comparison with the same assertion", funct
 
   it("Should compare tables correctly", function()
     -- assert.are.same({1}, {2})
-    local output = getoutput({1}, {2})
-    local ok = output:find("Passed in:\n(table) {\n *[1] = 2 }", nil, true)
+    local t1, t2 = {1}, {2}
+    local output = getoutput(t1, t2)
+    local ok = output:find("Passed in:\n("..tostring(t2)..") {\n *[1] = 2 }", nil, true)
     assert(ok, "Output check 1 failed, comparing table-table;\n    " .. output:gsub("\n","\n    "))
-    local ok = output:find("Expected:\n(table) {\n *[1] = 1 }", nil, true)
+    local ok = output:find("Expected:\n("..tostring(t1)..") {\n *[1] = 1 }", nil, true)
     assert(ok, "Output check 2 failed, comparing table-table;\n    " .. output:gsub("\n","\n    "))
   end)
 
@@ -301,18 +306,19 @@ describe("Output testing using custom failure message", function()
   end)
 
   it("Should convert objects to string", function()
-    local t = setmetatable({},{__tostring=function(t) return "empty table" end})
-    assert.is_equal("(table) { }", geterror("is_true", false, {}))
+    local t = {}
+    local t_tostring = setmetatable({},{__tostring=function(t) return "empty table" end})
+    assert.is_equal("("..tostring(t)..") { }", geterror("is_true", false, t))
     assert.is_equal("(number) 999", geterror("is_true", false, 999))
     assert.is_equal("(boolean) true", geterror("is_true", false, true))
     assert.is_equal("(boolean) false", geterror("is_true", false, false))
-    assert.is_equal("empty table", geterror("is_true", false, t))
+    assert.is_equal("empty table", geterror("is_true", false, t_tostring))
 
-    assert.is_equal("(table) { }", geterror2("is_true", false, {}))
+    assert.is_equal("("..tostring(t)..") { }", geterror2("is_true", false, t))
     assert.is_equal("(number) 999", geterror2("is_true", false, 999))
     assert.is_equal("(boolean) true", geterror2("is_true", false, true))
     assert.is_equal("(boolean) false", geterror2("is_true", false, false))
-    assert.is_equal("empty table", geterror2("is_true", false, t))
+    assert.is_equal("empty table", geterror2("is_true", false, t_tostring))
   end)
 
 end)
@@ -422,18 +428,19 @@ for _,ss in ipairs({"spy", "stub"}) do
     end)
 
     it("Should convert objects to string", function()
-      local t = setmetatable({},{__tostring=function(t) return "empty table" end})
-      assert.is_equal("(table) { }", geterror("was_called", {}, {}))
+      local t = {}
+      local t_tostring = setmetatable({},{__tostring=function(t) return "empty table" end})
+      assert.is_equal("("..tostring(t)..") { }", geterror("was_called", {}, t))
       assert.is_equal("(number) 999", geterror("was_called", {}, 999))
       assert.is_equal("(boolean) true", geterror("was_called", {}, true))
       assert.is_equal("(boolean) false", geterror("was_called", {}, false))
-      assert.is_equal("empty table", geterror("was_called", {}, t))
+      assert.is_equal("empty table", geterror("was_called", {}, t_tostring))
 
-      assert.is_equal("(table) { }", geterror2("was_called", {}, {}))
+      assert.is_equal("("..tostring(t)..") { }", geterror2("was_called", {}, t))
       assert.is_equal("(number) 999", geterror2("was_called", {}, 999))
       assert.is_equal("(boolean) true", geterror2("was_called", {}, true))
       assert.is_equal("(boolean) false", geterror2("was_called", {}, false))
-      assert.is_equal("empty table", geterror2("was_called", {}, t))
+      assert.is_equal("empty table", geterror2("was_called", {}, t_tostring))
     end)
 
   end)
diff --git a/src/formatters/init.lua b/src/formatters/init.lua
index ff69354..a92ad29 100644
--- a/src/formatters/init.lua
+++ b/src/formatters/init.lua
@@ -123,6 +123,20 @@ local function fmt_table(arg, fmtargs)
   local errcolor = assert:get_parameter("TableErrorHighlightColor") or "none"
   local crumbs = fmtargs and fmtargs.crumbs or {}
   local cache = {}
+  local type_desc
+
+  if getmetatable(arg) == nil then
+    type_desc = "(" .. tostring(arg) .. ") "
+  elseif not pcall(setmetatable, arg, getmetatable(arg)) then
+    -- cannot set same metatable, so it is protected, skip id
+    type_desc = "(table) "
+  else
+    -- unprotected metatable, temporary remove the mt
+    local mt = getmetatable(arg)
+    setmetatable(arg, nil)
+    type_desc = "(" .. tostring(arg) .. ") "
+    setmetatable(arg, mt)
+  end
 
   local function ft(t, l, with_crumbs)
     if showrec and cache[t] and cache[t] > 0 then
@@ -165,7 +179,7 @@ local function fmt_table(arg, fmtargs)
     return result .. " }"
   end
 
-  return "(table) " .. ft(arg, 1, true)
+  return type_desc .. ft(arg, 1, true)
 end
 
 local function fmt_function(arg)