diff --git a/include/cactus_rt/app.h b/include/cactus_rt/app.h
index 2e6b310..4abed16 100644
--- a/include/cactus_rt/app.h
+++ b/include/cactus_rt/app.h
@@ -23,9 +23,9 @@ class App {
    * @brief Creates an instance of the RT app. The app should always be created
    * before the threads as some global setup that can take place.
    *
-   * @param heap_size The heap size to reserve in bytes. Defaults to 512MB.
+   * @param heap_size The heap size to reserve in bytes. Defaults to 0 which means no heap memory will be reserved.
    */
-  explicit App(size_t heap_size = 512 * 1024 * 1024) : heap_size_(heap_size) {}
+  explicit App(size_t heap_size = 0) : heap_size_(heap_size) {}
   virtual ~App() = default;
 
   // Copy constructors
diff --git a/src/app.cc b/src/app.cc
index d233019..5ee1f1b 100644
--- a/src/app.cc
+++ b/src/app.cc
@@ -46,6 +46,8 @@ void App::ReserveHeap() const {
     return;
   }
 
+  SPDLOG_INFO("reserving {} bytes of heap memory", heap_size_);
+
   void* buf = malloc(heap_size_);
   if (buf == nullptr) {
     SPDLOG_ERROR("cannot malloc: {}", std::strerror(errno));