diff --git a/include/boost/python/detail/caller.hpp b/include/boost/python/detail/caller.hpp
index 1bd30bfb..557359f5 100644
--- a/include/boost/python/detail/caller.hpp
+++ b/include/boost/python/detail/caller.hpp
@@ -109,6 +109,23 @@ struct converter_target_type <void_result_to_python >
         return 0;
     }
 };
+
+// Generation of ret moved from caller_arity<N>::impl::signature to here due to "feature" in MSVC 15.7.2 with /O2
+// which left the ret uninitialized and caused segfaults in Python interpreter.
+template<class Policies, class Sig> const signature_element* get_ret()
+{
+    typedef BOOST_DEDUCED_TYPENAME Policies::template extract_return_type<Sig>::type rtype;
+    typedef typename select_result_converter<Policies, rtype>::type result_converter;
+
+    static const signature_element ret = {
+        (is_void<rtype>::value ? "void" : type_id<rtype>().name())
+        , &detail::converter_target_type<result_converter>::get_pytype
+        , boost::detail::indirect_traits::is_reference_to_non_const<rtype>::value 
+    };
+
+    return &ret;
+};
+
 #endif
 
     
@@ -229,16 +246,12 @@ struct caller_arity<N>
         {
             const signature_element * sig = detail::signature<Sig>::elements();
 #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
+            // MSVC 15.7.2, when compiling to /O2 left the static const signature_element ret, 
+            // originally defined here, uninitialized. This in turn led to SegFault in Python interpreter.
+            // Issue is resolved by moving the generation of ret to separate function in detail namespace (see above).
+            const signature_element * ret = detail::get_ret<Policies, Sig>();
 
-            typedef BOOST_DEDUCED_TYPENAME Policies::template extract_return_type<Sig>::type rtype;
-            typedef typename select_result_converter<Policies, rtype>::type result_converter;
-
-            static const signature_element ret = {
-                (is_void<rtype>::value ? "void" : type_id<rtype>().name())
-                , &detail::converter_target_type<result_converter>::get_pytype
-                , boost::detail::indirect_traits::is_reference_to_non_const<rtype>::value 
-            };
-            py_func_sig_info res = {sig, &ret };
+            py_func_sig_info res = {sig, ret };
 #else
             py_func_sig_info res = {sig, sig };
 #endif
diff --git a/include/boost/python/list.hpp b/include/boost/python/list.hpp
index 10fd40fd..0d5e2c8f 100644
--- a/include/boost/python/list.hpp
+++ b/include/boost/python/list.hpp
@@ -73,7 +73,7 @@ class list : public detail::list_base
     }
 
     template <class T>
-    long count(T const& value) const
+    ssize_t count(T const& value) const
     {
         return base::count(object(value));
     }
diff --git a/src/object/function.cpp b/src/object/function.cpp
index e612963b..9d4745d1 100644
--- a/src/object/function.cpp
+++ b/src/object/function.cpp
@@ -444,7 +444,9 @@ void function::add_to_namespace(
         if (dict == 0)
             throw_error_already_set();
 
+        assert(!PyErr_Occurred());
         handle<> existing(allow_null(::PyObject_GetItem(dict.get(), name.ptr())));
+        PyErr_Clear();
         
         if (existing)
         {
@@ -485,16 +487,15 @@ void function::add_to_namespace(
         if (new_func->name().is_none())
             new_func->m_name = name;
 
+        assert(!PyErr_Occurred());
         handle<> name_space_name(
             allow_null(::PyObject_GetAttrString(name_space.ptr(), const_cast<char*>("__name__"))));
+        PyErr_Clear();
         
         if (name_space_name)
             new_func->m_namespace = object(name_space_name);
     }
 
-    // The PyObject_GetAttrString() or PyObject_GetItem calls above may
-    // have left an active error
-    PyErr_Clear();
     if (PyObject_SetAttr(ns, name.ptr(), attribute.ptr()) < 0)
         throw_error_already_set();