diff --git a/esphome/core/automation.h b/esphome/core/automation.h
index ea522a4d2da..5f010521dce 100644
--- a/esphome/core/automation.h
+++ b/esphome/core/automation.h
@@ -608,7 +608,9 @@ template<typename... Ts> class ActionList {
 template<typename... Ts> class Automation {
  public:
   /// Default constructor for use with TriggerForwarder (no Trigger object needed).
-  Automation() = default;
+  // User provided, not "= default": `new(p) Automation()` would zero-fill .bss that is already zero.
+  // constexpr and noexcept keep the rest of the implicit constructor's contract.
+  constexpr Automation() noexcept {}
   explicit Automation(Trigger<Ts...> *trigger) { trigger->set_automation_parent(this); }
 
   void add_action(Action<Ts...> *action) { this->actions_.add_action(action); }