diff --git a/packages/helpermodules/utils/_thread_handler.py b/packages/helpermodules/utils/_thread_handler.py
index 33a108a4ed..50eda1dfee 100644
--- a/packages/helpermodules/utils/_thread_handler.py
+++ b/packages/helpermodules/utils/_thread_handler.py
@@ -14,13 +14,16 @@ def split_chunks(to_split, n):
     threads_splitted = list(split_chunks(threads, 50))
 
     for threads_chunk in threads_splitted:
+        threads_to_keep = []
+
         for thread in threads_chunk:
             if is_thread_alive(thread.name):
                 log.error(f"{thread.name} ist bereits aktiv und wird nicht erneut gestartet.")
                 not_finished_threads.append(thread.name)
-                threads_chunk.remove(thread)
+            else:
+                threads_to_keep.append(thread)
         # Start them all
-        for thread in threads_chunk:
+        for thread in threads_to_keep:
             thread.start()
 
         # Wait for all to complete