diff --git a/low_level_platform/api/CMakeLists.txt b/low_level_platform/api/CMakeLists.txt
index 18f774c14..b143b9a1f 100644
--- a/low_level_platform/api/CMakeLists.txt
+++ b/low_level_platform/api/CMakeLists.txt
@@ -15,7 +15,12 @@ elseif(${CMAKE_SYSTEM_NAME} STREQUAL "Rp2040")
     target_link_libraries(lf-low-level-platform-api INTERFACE pico_multicore)
     target_link_libraries(lf-low-level-platform-api INTERFACE pico_sync)
 elseif(${CMAKE_SYSTEM_NAME} STREQUAL "Stm32")
-    set(STM_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../../../STM_sdk)
+    if(DEFINED ENV{STM_SDK_DIR})
+        message(STATUS "STM_SDK_DIR is set to $ENV{STM_SDK_DIR}")
+    else()
+        message(FATAL_ERROR "The STM_SDK_DIR environment variable must be set to point to the directory generated by CUBEMX for you project.")
+    endif()
+    set(STM_SDK_DIR $ENV{STM_SDK_DIR})
     set(MCU_FAMILY STM32F4xx)
     set(MCU_MODEL STM32F446xx)
     set(CPU_PARAMETERS -mcpu=cortex-m4 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=softfp)