diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4c47f89..5785994 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## 3.4.2
+
+### Changed
+
+* [#402](https://github.com/stlehmann/pyads/pull/402) Universal DLL path for TwinCat 4026 and 4024 
+
 ## 3.4.1
 
 ### Changed
@@ -111,7 +117,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Changed
 * fixed error with source distribution not containing adslib directory
- 
+
 ### Removed
 
 ## 3.3.1
diff --git a/pyads/__init__.py b/pyads/__init__.py
index bbde837..f4d0abd 100644
--- a/pyads/__init__.py
+++ b/pyads/__init__.py
@@ -118,4 +118,4 @@
 
 from .symbol import AdsSymbol
 
-__version__ = '3.4.1'
+__version__ = '3.4.2'
diff --git a/pyads/pyads_ex.py b/pyads/pyads_ex.py
index 66b6bdd..6a7e445 100644
--- a/pyads/pyads_ex.py
+++ b/pyads/pyads_ex.py
@@ -57,22 +57,16 @@
 # load dynamic ADS library
 if platform_is_windows():  # pragma: no cover, skip Windows test
     dlldir_handle = None
-    if sys.version_info >= (3, 8):
+    if sys.version_info >= (3, 8) and "TWINCAT3DIR" in os.environ:
         # Starting with version 3.8, CPython does not consider the PATH environment
         # variable any more when resolving DLL paths. The following works with the default
         # installation of the Beckhoff TwinCAT ADS DLL.
-        if "TWINCATSDK" in os.environ:
-            dll_path = os.environ["TWINCATSDK"] + "\\..\\.."
-            if platform.architecture()[0] == "64bit":
-                dll_path += "\\Common64"
-            else:
-                dll_path += "\\Common32"
-            dlldir_handle = os.add_dll_directory(dll_path)
-        elif "TWINCAT3DIR" in os.environ:
-            dll_path = os.environ["TWINCAT3DIR"] + "\\..\\AdsApi\\TcAdsDll"
-            if platform.architecture()[0] == "64bit":
-                dll_path += "\\x64"
-            dlldir_handle = os.add_dll_directory(dll_path)
+        dll_path = os.environ["TWINCAT3DIR"] + "\\.."
+        if platform.architecture()[0] == "64bit":
+            dll_path += "\\Common64"
+        else:
+            dll_path += "\\Common32"
+        dlldir_handle = os.add_dll_directory(dll_path)
     try:
         _adsDLL = ctypes.WinDLL("TcAdsDll.dll")  # type: ignore
     finally:
diff --git a/tox.ini b/tox.ini
index fa54e78..aa05b25 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@ commands = discover
 deps = discover
 changedir = tests
 whitelist_externals=*
-passenv = TWINCATSDK TWINCAT3DIR
+passenv = TWINCAT3DIR
 
 [pytest]
 testpaths = tests