diff --git a/bootstrap.py b/bootstrap.py
index f26232ab..c2f4ebe3 100755
--- a/bootstrap.py
+++ b/bootstrap.py
@@ -55,7 +55,7 @@ args = parser.parse_args()
 # general variables
 include = [ '.', './include' ]
 depends = [os.path.join('Catch', 'include')]
-cxxflags = [ '-Wall', '-Wextra', '-pedantic', '-pedantic-errors', '-std=c++14', '-ftemplate-depth=1024' ]
+cxxflags = [ '-Wall', '-Wextra', '-Wpedantic', '-pedantic', '-pedantic-errors', '-std=c++14', '-ftemplate-depth=1024' ]
 cxxflags.extend([p for p in re.split("( |\\\".*?\\\"|'.*?')", args.cxx_flags) if p.strip()])
 ldflags = []
 script_dir = os.path.dirname(os.path.realpath(sys.argv[0]))
diff --git a/sol/protected_function.hpp b/sol/protected_function.hpp
index ed2861e7..009f7910 100644
--- a/sol/protected_function.hpp
+++ b/sol/protected_function.hpp
@@ -83,7 +83,6 @@ private:
     }
 
     protected_function_result invoke(types<>, std::index_sequence<>, std::ptrdiff_t n, handler& h) const {
-        bool handlerpushed = error_handler.valid();
         int stacksize = lua_gettop(lua_state());
         int firstreturn = std::max(1, stacksize - static_cast<int>(n) - 1);
         int returncount = 0;
diff --git a/sol/stack_check.hpp b/sol/stack_check.hpp
index 8be8885a..9462f9d7 100644
--- a/sol/stack_check.hpp
+++ b/sol/stack_check.hpp
@@ -290,7 +290,7 @@ template<typename T, typename C>
 struct checker<optional<T>, type::poly, C> {
     template <typename Handler>
     static bool check(lua_State* L, int index, Handler&& handler) {
-        return stack::check<T>(L, index, std::forward<Handler>(handler));
+        return stack::check<nil_t>(L, index, no_panic) || stack::check<T>(L, index, std::forward<Handler>(handler));
     }
 };
 } // stack