diff --git a/esphome/core/application.cpp b/esphome/core/application.cpp
index f963afa597..e51bc22f15 100644
--- a/esphome/core/application.cpp
+++ b/esphome/core/application.cpp
@@ -79,7 +79,6 @@ static void insertion_sort_by_priority(Iterator first, Iterator last) {
   }
 }
 
-void Application::register_component_(Component *comp) { this->components_.push_back(comp); }
 void Application::setup() {
   ESP_LOGI(TAG, "Running through setup()");
   ESP_LOGV(TAG, "Sorting components by setup priority");
diff --git a/esphome/core/application.h b/esphome/core/application.h
index ba3ce13291..9f4672b75d 100644
--- a/esphome/core/application.h
+++ b/esphome/core/application.h
@@ -521,7 +521,7 @@ class Application {
 #endif
 #endif
 
-  void register_component_(Component *comp);
+  inline void register_component_(Component *comp) { this->components_.push_back(comp); }
 
   void calculate_looping_components_();
   void add_looping_components_by_state_(bool match_loop_done);