diff --git a/customtkinter/windows/widgets/theme/__init__.py b/customtkinter/windows/widgets/theme/__init__.py
index bd7395a..8931f35 100644
--- a/customtkinter/windows/widgets/theme/__init__.py
+++ b/customtkinter/windows/widgets/theme/__init__.py
@@ -4,6 +4,6 @@ from .theme_manager import ThemeManager
 try:
     ThemeManager.load_theme("blue")
 except FileNotFoundError as err:
-    raise FileNotFoundError(f"{err}\n\nThe .json theme file for CustomTkinter could not be found.\n" +
+    raise FileNotFoundError(f"{err}\nThe .json theme file for CustomTkinter could not be found.\n" +
                             f"If packaging with pyinstaller was used, have a look at the wiki:\n" +
                             f"https://github.com/TomSchimansky/CustomTkinter/wiki/Packaging#windows-pyinstaller-auto-py-to-exe")
diff --git a/customtkinter/windows/widgets/theme/theme_manager.py b/customtkinter/windows/widgets/theme/theme_manager.py
index e04b679..f871d49 100644
--- a/customtkinter/windows/widgets/theme/theme_manager.py
+++ b/customtkinter/windows/widgets/theme/theme_manager.py
@@ -1,5 +1,6 @@
 import sys
 import os
+import pathlib
 import json
 from typing import List, Union
 
@@ -15,7 +16,8 @@ class ThemeManager:
         script_directory = os.path.dirname(os.path.abspath(__file__))
 
         if theme_name_or_path in cls._built_in_themes:
-            with open(os.path.join(script_directory, "../../../assets", "themes", f"{theme_name_or_path}.json"), "r") as f:
+            customtkinter_path = pathlib.Path(script_directory).parent.parent.parent
+            with open(os.path.join(customtkinter_path, "assets", "themes", f"{theme_name_or_path}.json"), "r") as f:
                 cls.theme = json.load(f)
         else:
             with open(theme_name_or_path, "r") as f: