diff --git a/esphome/core/entity_base.h b/esphome/core/entity_base.h
index 91137b4853..e17a649051 100644
--- a/esphome/core/entity_base.h
+++ b/esphome/core/entity_base.h
@@ -89,6 +89,8 @@ class EntityBase {
   uint32_t get_preference_hash() {
 #ifdef USE_DEVICES
     // Combine object_id_hash with device_id to ensure uniqueness across devices
+    // Note: device_id is 0 for the main device, so XORing with 0 preserves the original hash
+    // This ensures backward compatibility for existing single-device configurations
     return this->get_object_id_hash() ^ this->get_device_id();
 #else
     // Without devices, just use object_id_hash as before