diff --git a/components/bootloader/project_include.cmake b/components/bootloader/project_include.cmake
index 485a786f9b..12cf17dc70 100644
--- a/components/bootloader/project_include.cmake
+++ b/components/bootloader/project_include.cmake
@@ -117,11 +117,12 @@ idf_build_get_property(python PYTHON)
 idf_build_get_property(extra_cmake_args EXTRA_CMAKE_ARGS)
 
 # BOOTLOADER_EXTRA_COMPONENT_DIRS may have been set by the `main` component, do not overwrite it
-list(APPEND BOOTLOADER_EXTRA_COMPONENT_DIRS "${CMAKE_CURRENT_LIST_DIR}")
+idf_build_get_property(bootloader_extra_component_dirs BOOTLOADER_EXTRA_COMPONENT_DIRS)
+list(APPEND bootloader_extra_component_dirs "${CMAKE_CURRENT_LIST_DIR}")
 
 # We cannot pass lists as a parameter to the external project without modifying the ';' separator
 string(REPLACE ";" "|" BOOTLOADER_IGNORE_EXTRA_COMPONENT "${BOOTLOADER_IGNORE_EXTRA_COMPONENT}")
-string(REPLACE ";" "|" BOOTLOADER_EXTRA_COMPONENT_DIRS "${BOOTLOADER_EXTRA_COMPONENT_DIRS}")
+string(REPLACE ";" "|" bootloader_extra_component_dirs "${bootloader_extra_component_dirs}")
 
 externalproject_add(bootloader
     SOURCE_DIR "${CMAKE_CURRENT_LIST_DIR}/subproject"
@@ -131,7 +132,7 @@ externalproject_add(bootloader
     LIST_SEPARATOR |
     CMAKE_ARGS  -DSDKCONFIG=${sdkconfig} -DIDF_PATH=${idf_path} -DIDF_TARGET=${idf_target}
                 -DPYTHON_DEPS_CHECKED=1 -DPYTHON=${python}
-                -DEXTRA_COMPONENT_DIRS=${BOOTLOADER_EXTRA_COMPONENT_DIRS}
+                -DEXTRA_COMPONENT_DIRS=${bootloader_extra_component_dirs}
                 -DPROJECT_SOURCE_DIR=${PROJECT_SOURCE_DIR}
                 -DIGNORE_EXTRA_COMPONENT=${BOOTLOADER_IGNORE_EXTRA_COMPONENT}
                 ${sign_key_arg} ${ver_key_arg}
diff --git a/examples/custom_bootloader/bootloader_extra_dir/CMakeLists.txt b/examples/custom_bootloader/bootloader_extra_dir/CMakeLists.txt
index 64ae357407..77e21c4ce6 100644
--- a/examples/custom_bootloader/bootloader_extra_dir/CMakeLists.txt
+++ b/examples/custom_bootloader/bootloader_extra_dir/CMakeLists.txt
@@ -6,6 +6,6 @@ cmake_minimum_required(VERSION 3.16)
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 
-set(BOOTLOADER_EXTRA_COMPONENT_DIRS "${CMAKE_CURRENT_LIST_DIR}/extra_bootloader_components/")
+idf_build_set_property(BOOTLOADER_EXTRA_COMPONENT_DIRS "${CMAKE_CURRENT_LIST_DIR}/extra_bootloader_components/" APPEND)
 
 project(main)