diff --git a/libuavcan/include/uavcan/node/node.hpp b/libuavcan/include/uavcan/node/node.hpp
index d270c8adf9..3f34d27593 100644
--- a/libuavcan/include/uavcan/node/node.hpp
+++ b/libuavcan/include/uavcan/node/node.hpp
@@ -34,7 +34,7 @@ namespace uavcan
  *                          Please refer to the documentation for details.
  *                          If this value is zero, the constructor will accept a reference to user-provided allocator.
  */
-template <std::size_t MemPoolSize>
+template <std::size_t MemPoolSize = 0>
 class UAVCAN_EXPORT Node : public INode
 {
     typedef typename
diff --git a/libuavcan/include/uavcan/node/sub_node.hpp b/libuavcan/include/uavcan/node/sub_node.hpp
index 438d1d6815..35b80492e5 100644
--- a/libuavcan/include/uavcan/node/sub_node.hpp
+++ b/libuavcan/include/uavcan/node/sub_node.hpp
@@ -20,7 +20,7 @@ namespace uavcan
  * Please refer to the @ref Node<> for documentation concerning the template arguments; refer to the tutorials
  * to lean how to use libuavcan in multiprocess applications.
  */
-template <std::size_t MemPoolSize>
+template <std::size_t MemPoolSize = 0>
 class UAVCAN_EXPORT SubNode : public INode
 {
     typedef typename