diff --git a/test/storage_adaptor_test.cpp b/test/storage_adaptor_test.cpp
index d0a05300..7f4f67bb 100644
--- a/test/storage_adaptor_test.cpp
+++ b/test/storage_adaptor_test.cpp
@@ -247,28 +247,29 @@ int main() {
                          tracing_allocator<std::pair<const std::size_t, double>>>;
     using A = storage_adaptor<map>;
     auto a = A(map(alloc));
+    // MSVC implementation allocates some structures for debugging
+    const auto baseline = db.sum.first;
     a.reset(10);
-    BOOST_TEST_EQ(db.sum().first, 0); // nothing allocated yet
+    BOOST_TEST_EQ(db.sum.first, baseline); // nothing allocated yet
     BOOST_TEST_EQ(static_cast<const A&>(a)[0],
                   0);       // query on const reference does not allocate
     BOOST_TEST_EQ(a[9], 0); // query on writeable reference allocates
-    BOOST_TEST_EQ(db.sum().first, 1);
+    BOOST_TEST_EQ(db.sum.first, baseline + 1);
 
     a(5);
     BOOST_TEST_EQ(a[0], 0);
     BOOST_TEST_EQ(a[5], 1);
     BOOST_TEST_EQ(a[9], 0);
-    BOOST_TEST_EQ(db.sum().first, 3);
+    BOOST_TEST_EQ(db.sum.first, baseline + 3);
     a *= 2;
     BOOST_TEST_EQ(a[5], 2);
-    BOOST_TEST_EQ(db.sum().first, 3);
+    BOOST_TEST_EQ(db.sum.first, baseline + 3);
 
     auto b = storage_adaptor<std::vector<int>>();
     b.reset(5);
     b(2);
     a = b;
-    BOOST_TEST_EQ(db.sum().second, 3); // old allocations were freed
-    BOOST_TEST_EQ(db.sum().first, 4);  // only one new allocation for non-zero value
+    BOOST_TEST_EQ(db.sum.first, baseline + 4);  // only one new allocation for non-zero value
   }
 
   return boost::report_errors();
diff --git a/test/utility_allocator.hpp b/test/utility_allocator.hpp
index 6230f9ae..09b0165f 100644
--- a/test/utility_allocator.hpp
+++ b/test/utility_allocator.hpp
@@ -23,14 +23,7 @@ struct tracing_allocator_db : std::unordered_map<const boost::core::typeinfo*,
     return this->operator[](&BOOST_CORE_TYPEID(T));
   }
 
-  std::pair<std::size_t, std::size_t> sum() {
-    std::pair<std::size_t, std::size_t> result(0, 0);
-    for (const auto& p : *this) {
-      result.first += p.second.first;
-      result.second += p.second.second;
-    }
-    return result;
-  }
+  std::pair<std::size_t, std::size_t> sum;
 };
 
 template <class T>
@@ -46,12 +39,12 @@ struct tracing_allocator {
   ~tracing_allocator() noexcept {}
 
   T* allocate(std::size_t n) {
-    if (db) { db->at<T>().first += n; }
+    if (db) { db->at<T>().first += n; db->sum.first += n; }
     return static_cast<T*>(::operator new(n * sizeof(T)));
   }
 
   void deallocate(T* p, std::size_t n) {
-    if (db) { db->at<T>().second += n; }
+    if (db) { db->at<T>().second += n; db->sum.second += n; }
     ::operator delete((void*)p);
   }
 };