diff --git a/gns3server/controller/import_project.py b/gns3server/controller/import_project.py
index 4af3717ce..4e882ae75 100644
--- a/gns3server/controller/import_project.py
+++ b/gns3server/controller/import_project.py
@@ -17,7 +17,6 @@
 
 import os
 import sys
-import stat
 import json
 import uuid
 import shutil
diff --git a/gns3server/utils/asyncio/aiozipstream.py b/gns3server/utils/asyncio/aiozipstream.py
index 4850eb3b0..c8f69c8e2 100644
--- a/gns3server/utils/asyncio/aiozipstream.py
+++ b/gns3server/utils/asyncio/aiozipstream.py
@@ -71,10 +71,9 @@ def _get_compressor(compress_type, compresslevel=None):
     elif compress_type == ZIP_ZSTANDARD:
         import zstandard as zstd
         if compresslevel is not None:
-            #params = zstd.ZstdCompressionParameters.from_level(compresslevel, threads=-1, enable_ldm=True, window_log=31)
-            #return zstd.ZstdCompressor(compression_params=params).compressobj()
-            return zstd.ZstdCompressor(level=compresslevel).compressobj()
-        return zstd.ZstdCompressor().compressobj()
+            # for threads param a value of -1 means to set the number of threads to the number of detected logical CPUs
+            return zstd.ZstdCompressor(level=compresslevel, threads=-1).compressobj()
+        return zstd.ZstdCompressor(threads=-1).compressobj()
     else:
         return None
 
diff --git a/gns3server/utils/zipfile_zstd/_zipfile.py b/gns3server/utils/zipfile_zstd/_zipfile.py
index 5748ad94d..c082fe49f 100644
--- a/gns3server/utils/zipfile_zstd/_zipfile.py
+++ b/gns3server/utils/zipfile_zstd/_zipfile.py
@@ -42,7 +42,7 @@ if 'compresslevel' in inspect.signature(zipfile._get_compressor).parameters:
         if compress_type == zipfile.ZIP_ZSTANDARD:
             if compresslevel is None:
                 compresslevel = 3
-            return zstd.ZstdCompressor(level=compresslevel, threads=12).compressobj()
+            return zstd.ZstdCompressor(level=compresslevel, threads=-1).compressobj()
         else:
             return patch.originals['_get_compressor'](compress_type, compresslevel=compresslevel)
 else:
@@ -51,7 +51,7 @@ else:
         if compress_type == zipfile.ZIP_ZSTANDARD:
             if compresslevel is None:
                 compresslevel = 3
-            return zstd.ZstdCompressor(level=compresslevel, threads=12).compressobj()
+            return zstd.ZstdCompressor(level=compresslevel, threads=-1).compressobj()
         else:
             return patch.originals['_get_compressor'](compress_type)