diff --git a/include/pybind11/detail/common.h b/include/pybind11/detail/common.h
index 6d328ba8b8..427f1c87d4 100644
--- a/include/pybind11/detail/common.h
+++ b/include/pybind11/detail/common.h
@@ -581,6 +581,11 @@ template <typename T, typename... Us> using deferred_t = typename deferred_type<
 template <typename Base, typename Derived> using is_strict_base_of = bool_constant<
     std::is_base_of<Base, Derived>::value && !std::is_same<Base, Derived>::value>;
 
+/// Like is_base_of, but also requires that the base type is accessible (i.e. that a Derived pointer
+/// can be converted to a Base pointer)
+template <typename Base, typename Derived> using is_accessible_base_of = bool_constant<
+    std::is_base_of<Base, Derived>::value && std::is_convertible<Derived *, Base *>::value>;
+
 template <template<typename...> class Base>
 struct is_template_base_of_impl {
     template <typename... Us> static std::true_type check(Base<Us...> *);
diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h
index 59af022927..90b8ebcc63 100644
--- a/include/pybind11/pybind11.h
+++ b/include/pybind11/pybind11.h
@@ -997,10 +997,18 @@ template <typename /*Derived*/, typename F>
 auto method_adaptor(F &&f) -> decltype(std::forward<F>(f)) { return std::forward<F>(f); }
 
 template <typename Derived, typename Return, typename Class, typename... Args>
-auto method_adaptor(Return (Class::*pmf)(Args...)) -> Return (Derived::*)(Args...) { return pmf; }
+auto method_adaptor(Return (Class::*pmf)(Args...)) -> Return (Derived::*)(Args...) {
+    static_assert(detail::is_accessible_base_of<Class, Derived>::value,
+        "Cannot bind an inaccessible base class method; use a lambda definition instead");
+    return pmf;
+}
 
 template <typename Derived, typename Return, typename Class, typename... Args>
-auto method_adaptor(Return (Class::*pmf)(Args...) const) -> Return (Derived::*)(Args...) const { return pmf; }
+auto method_adaptor(Return (Class::*pmf)(Args...) const) -> Return (Derived::*)(Args...) const {
+    static_assert(detail::is_accessible_base_of<Class, Derived>::value,
+        "Cannot bind an inaccessible base class method; use a lambda definition instead");
+    return pmf;
+}
 
 template <typename type_, typename... options>
 class class_ : public detail::generic_type {