diff --git a/ngsolve_addon.cmake b/ngsolve_addon.cmake
index 1db6b35..fb64641 100644
--- a/ngsolve_addon.cmake
+++ b/ngsolve_addon.cmake
@@ -95,9 +95,25 @@ endif()
 macro(ngsolve_generate_stub_files module_name)
   set(stubgen_generation_code "execute_process(WORKING_DIRECTORY ${stubgen_working_dir} COMMAND ${Python3_EXECUTABLE} -m pybind11_stubgen --ignore-all-errors -o ${CMAKE_CURRENT_BINARY_DIR}/stubs ${module_name})")
   set(stubgen_directory "${CMAKE_CURRENT_BINARY_DIR}/stubs/${module_name}/")
+  set(stubgen_file "${CMAKE_CURRENT_BINARY_DIR}/stubs/${module_name}.pyi")
+  set(stubgen_install_destination ${ADDON_INSTALL_DIR_PYTHON}/${module_name}/)
 
   install(CODE ${stubgen_generation_code})
-  install(DIRECTORY ${stubgen_directory} DESTINATION ${ADDON_INSTALL_DIR_PYTHON}/${module_name})
+
+  if(NOT IS_DIRECTORY ${CMAKE_INSTALL_PREFIX}/${stubgen_install_destination})
+    message(
+      FATAL_ERROR
+      "stub files cannot be installed to ${CMAKE_INSTALL_PREFIX}/${stubgen_install_destination}, the folder does not exist."
+    )
+  endif()
+
+  if(EXISTS ${stubgen_file})
+    install(FILES ${stubgen_file} DESTINATION ${stubgen_install_destination})
+  elseif(IS_DIRECTORY ${stubgen_directory})
+    install(DIRECTORY ${stubgen_directory} DESTINATION ${stubgen_install_destination})
+  else()
+    message(FATAL_ERROR "Unable to locate and install stub files.")
+  endif()
 endmacro()
 
 message(STATUS "Install dir: ${CMAKE_INSTALL_PREFIX}")