diff --git a/setup.py b/setup.py
index 59d14cc0..ae19c361 100644
--- a/setup.py
+++ b/setup.py
@@ -53,7 +53,8 @@
     'grpcio',
     'ruamel.yaml>=0.15.89',
     'pyzmq>=17.1.0',
-    'aiohttp']
+    'aiohttp',
+    'sklearn']
 
 # using pip install gnes[xx] is depreciated
 # extras_dep is kept for legacy issue, will be removed soon