diff --git a/cmake/util.cmake b/cmake/util.cmake
index ff954b7a4e..1414421aa0 100644
--- a/cmake/util.cmake
+++ b/cmake/util.cmake
@@ -11,7 +11,9 @@ function(mbed_add_cmake_directory_if_labels PREFIX)
         # assumption: relative path, no need to check for absolute here
         set(path ${CMAKE_CURRENT_SOURCE_DIR}/${key})
         if (EXISTS ${path})
-            add_subdirectory(${path})
+            if (EXISTS  "${path}/CMakeLists.txt")
+                add_subdirectory(${path})
+            endif()
         endif()
     endforeach()
 endfunction()