diff --git a/3rdparty/CMakeLists.txt b/3rdparty/CMakeLists.txt
index 18945e52ee..37480f2cfd 100644
--- a/3rdparty/CMakeLists.txt
+++ b/3rdparty/CMakeLists.txt
@@ -4,11 +4,7 @@ list (APPEND thirdparty_inc_public)
 list (APPEND thirdparty_inc)
 list (APPEND thirdparty_def)
 
-execute_process(COMMAND ${MBEDTLS_PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/../scripts/config.py -f ${CMAKE_CURRENT_SOURCE_DIR}/../include/mbedtls/config.h get MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED RESULT_VARIABLE result)
-
-if(${result} EQUAL 0)
-    add_subdirectory(everest)
-endif()
+add_subdirectory(everest)
 
 set(thirdparty_src ${thirdparty_src} PARENT_SCOPE)
 set(thirdparty_lib ${thirdparty_lib} PARENT_SCOPE)
diff --git a/ChangeLog.d/fix-cmake-3rdparty-custom-config.txt b/ChangeLog.d/fix-cmake-3rdparty-custom-config.txt
new file mode 100644
index 0000000000..c52aa3deee
--- /dev/null
+++ b/ChangeLog.d/fix-cmake-3rdparty-custom-config.txt
@@ -0,0 +1,3 @@
+Bugfix
+   * Fix the build with CMake when Everest is enabled through
+     a user configuration file or the compiler command line. Fixes #8165.