diff --git a/modules/find/find_include_files.cmake b/modules/find/find_include_files.cmake
index 5e40bc1..2ef99b9 100644
--- a/modules/find/find_include_files.cmake
+++ b/modules/find/find_include_files.cmake
@@ -15,4 +15,5 @@ function(_find_include_dir _names _hints _result)
     if(${_all_include_files_work})
         set(${_result} ${_include_dir} PARENT_SCOPE)
     endif()
+    unset(_include_dir CACHE)
 endfunction()
diff --git a/modules/find/find_libraries.cmake b/modules/find/find_libraries.cmake
index 0683d8c..3b060a0 100644
--- a/modules/find/find_libraries.cmake
+++ b/modules/find/find_libraries.cmake
@@ -19,4 +19,5 @@ function(_find_library _names _check_function _result)
     if(${_library_works})
         set(${_result} ${_lib} PARENT_SCOPE)
     endif()
+    unset(_lib CACHE)
 endfunction()