diff --git a/rclcpp/include/rclcpp/memory_strategies.hpp b/rclcpp/include/rclcpp/memory_strategies.hpp
index 2887426..b69ed51 100644
--- a/rclcpp/include/rclcpp/memory_strategies.hpp
+++ b/rclcpp/include/rclcpp/memory_strategies.hpp
@@ -31,10 +31,10 @@ using rclcpp::memory_strategies::allocator_memory_strategy::AllocatorMemoryStrat
 }  /* memory_strategies */
 
 namespace memory_strategy {
-  MemoryStrategy::SharedPtr create_default_strategy() {
+  static MemoryStrategy::SharedPtr create_default_strategy() {
     return std::make_shared<memory_strategies::allocator_memory_strategy::AllocatorMemoryStrategy<>>();
   }
-}
+} /* memory_strategy */
 
 }  /* rclcpp */
 
diff --git a/rclcpp/include/rclcpp/memory_strategy.hpp b/rclcpp/include/rclcpp/memory_strategy.hpp
index 86acfb8..22291bd 100644
--- a/rclcpp/include/rclcpp/memory_strategy.hpp
+++ b/rclcpp/include/rclcpp/memory_strategy.hpp
@@ -38,7 +38,7 @@ class MemoryStrategy
 {
 public:
   RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(MemoryStrategy);
-  using WeakNodeVector = std::vector<std::weak_ptr<rclcpp::node::Node>>>;
+  using WeakNodeVector = typename std::vector<std::weak_ptr<rclcpp::node::Node>>>;
 
   // return the new number of subscribers
   virtual size_t fill_subscriber_handles(void ** ptr) = 0;
diff --git a/rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp b/rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp
index f47b95c..c0f86fc 100644
--- a/rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp
+++ b/rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp
@@ -43,8 +43,6 @@ class AllocatorMemoryStrategy : public memory_strategy::MemoryStrategy
 public:
   RCLCPP_SMART_PTR_DEFINITIONS(AllocatorMemoryStrategy<Alloc>);
 
-  using WeakNode = std::weak_ptr<rclcpp::node::Node>>;
-  using NodeVector = std::vector<WeakNode>;
 
   using ExecAllocTraits = allocator::AllocRebind<executor::AnyExecutable, Alloc>;
   using ExecAlloc = typename ExecAllocTraits::allocator_type;
@@ -52,6 +50,8 @@ public:
   using VoidAllocTraits = typename allocator::AllocRebind<void *, Alloc>;
   using VoidAlloc = typename VoidAllocTraits::allocator_type;
 
+  using NodeVector = typename std::vector<std::weak_ptr<rclcpp::node::Node>>>;
+
   AllocatorMemoryStrategy(std::shared_ptr<Alloc> allocator)
   {
     executable_allocator_ = std::make_shared<ExecAlloc>(*allocator.get());