diff --git a/esphome/core/application.cpp b/esphome/core/application.cpp
index d9f29259d03..56138535a38 100644
--- a/esphome/core/application.cpp
+++ b/esphome/core/application.cpp
@@ -159,9 +159,8 @@ void Application::setup() {
 
 void Application::process_dump_config_() {
   if (this->dump_config_at_ == 0) {
-    char build_time_str[Application::BUILD_TIME_STR_SIZE];
-    this->get_build_time_string(build_time_str);
-    ESP_LOGI(TAG, "ESPHome version " ESPHOME_VERSION " compiled on %s", build_time_str);
+    // %s reads flash on ESP8266, so the build time needs no RAM copy
+    ESP_LOGI(TAG, "ESPHome version " ESPHOME_VERSION " compiled on %s", ESPHOME_BUILD_TIME_STR);
 #ifdef ESPHOME_PROJECT_NAME
     ESP_LOGI(TAG, "Project " ESPHOME_PROJECT_NAME " version " ESPHOME_PROJECT_VERSION);
 #endif