diff --git a/core/common_radiohdl.py b/core/common_radiohdl.py
index 4bcc57ab7de5b7f9887638f17eb142ad7228f6aa..78e12a00a2cba701605ff30aa5b0f4e922360260 100644
--- a/core/common_radiohdl.py
+++ b/core/common_radiohdl.py
@@ -2,18 +2,18 @@
 #
 # Copyright 2018 Stichting Nederlandse Wetenschappelijk Onderzoek Instituten
 # ASTRON Netherlands Institute for Radio Astronomy
-# 
+#
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
-# 
+#
 #    http://www.apache.org/licenses/LICENSE-2.0
-# 
+#
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
-# limitations under the License. 
+# limitations under the License.
 #
 ###############################################################################
 
@@ -76,7 +76,7 @@ def method_name(caller_depth=0):
     Returns the name of the caller method.
     """
     # Note: inspect.stack()[0][3] would return the name of this method.
-    return inspect.stack()[caller_depth+1][3]
+    return inspect.stack()[caller_depth + 1][3]
 
 
 def mkdir(path):
diff --git a/regressiontest/modelsim_regression_test_vhdl.py b/regressiontest/modelsim_regression_test_vhdl.py
index 68988248d62215a0390b0d48f4f685177dc1ada1..0e0e089c822786c55f6f92e27e2d39443e894f21 100755
--- a/regressiontest/modelsim_regression_test_vhdl.py
+++ b/regressiontest/modelsim_regression_test_vhdl.py
@@ -105,11 +105,10 @@ def main(args, time_ordered_tb_dict):
     # start 'n_proc' tb worker processes
     logger.info("Run all tests using %d workers", n_proc)
     modelsim_log_path = os.path.join(args.log_path, "modelsim")
-    my_env = os.environ.copy()
     workers = []
     for i in range(n_proc):
         worker_id = i + 1
-        worker = TestBenchWorker(worker_id, my_env, control_queue[i], task_queue, response_queue, MK_TIMEOUT, SIM_TIMEOUT, modelsim_log_path)
+        worker = TestBenchWorker(worker_id, control_queue[i], task_queue, response_queue, MK_TIMEOUT, SIM_TIMEOUT, modelsim_log_path)
         workers.append(worker)
         worker.start()
 
@@ -420,10 +419,9 @@ def generate_email_report(
 class TestBenchWorker(multiprocessing.Process):
     """TestBenchWorker class is a process that will check for tasks to process in the in_queue"""
 
-    def __init__(self, worker_id, my_env, control_queue, in_queue, out_queue, max_mk_time, max_sim_time, log_path):
+    def __init__(self, worker_id, control_queue, in_queue, out_queue, max_mk_time, max_sim_time, log_path):
         multiprocessing.Process.__init__(self)
         self._id = worker_id
-        self._my_env = my_env
         self._ctrl = control_queue
         self._in = in_queue
         self._out = out_queue
@@ -454,8 +452,8 @@ class TestBenchWorker(multiprocessing.Process):
         if not os.path.exists(sim_dir):
             os.mkdir(sim_dir)
 
-        os.putenv("HDL_IOFILE_SIM_DIR", sim_dir)
-        self.terminal = Terminal(print_stdout_on_timeout=True, env=my_env)
+        os.environ["HDL_IOFILE_SIM_DIR"] = sim_dir
+        self.terminal = Terminal(print_stdout_on_timeout=True)
         self.terminal.run_cmd(f"rm -rf {sim_dir}/*")
         print(self.terminal.stdout())