diff --git a/deployment/pypi/setup.py b/deployment/pypi/setup.py
index 9ed6c685f0..f1830cdef9 100644
--- a/deployment/pypi/setup.py
+++ b/deployment/pypi/setup.py
@@ -62,7 +62,7 @@
         'scipy',
         'coverage',
         'colorama',
-        'sklearn'
+        'scikit-learn==0.20'
     ],
     classifiers = [
         'Programming Language :: Python :: 3',
diff --git a/docs/requirements.txt b/docs/requirements.txt
index a15d2dfe64..ff3b15f98d 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -9,4 +9,4 @@ json_tricks
 numpy
 scipy
 coverage
-sklearn
+scikit-learn==0.20
diff --git a/setup.py b/setup.py
index 0988302b92..1c07d5747b 100644
--- a/setup.py
+++ b/setup.py
@@ -40,7 +40,7 @@ def read(fname):
         'schema',
         'PythonWebHDFS',
         'colorama',
-        'sklearn'
+        'scikit-learn==0.20'
     ],
 
     entry_points = {
diff --git a/src/sdk/pynni/nni/metis_tuner/requirments.txt b/src/sdk/pynni/nni/metis_tuner/requirments.txt
index 044bdd7586..05c74c49ca 100644
--- a/src/sdk/pynni/nni/metis_tuner/requirments.txt
+++ b/src/sdk/pynni/nni/metis_tuner/requirments.txt
@@ -1 +1 @@
-sklearn
\ No newline at end of file
+scikit-learn==0.20
\ No newline at end of file
diff --git a/src/sdk/pynni/requirements.txt b/src/sdk/pynni/requirements.txt
index d44ec3a072..885c909ca8 100644
--- a/src/sdk/pynni/requirements.txt
+++ b/src/sdk/pynni/requirements.txt
@@ -7,4 +7,4 @@ scipy
 hyperopt==0.1.2
 
 # metis tuner
-sklearn
+scikit-learn==0.20