diff --git a/PY2.md b/PY2.md
index 94c5945..da2c587 100644
--- a/PY2.md
+++ b/PY2.md
@@ -16,7 +16,8 @@ NOTE. It will require legacy versions of the following packages:
 * numpy<1.17
 * scipy<1.3
 * scikit-learn>=0.18,<0.21
+
 There is a dedicated branch on GitHub called `py2` with appropriate requirements in `setup.py`.  
 Installation:  
 
-`pip install https://github.com/vecxoz/vecstack/archive/py2.zip`
\ No newline at end of file
+`pip install https://github.com/vecxoz/vecstack/archive/py2.zip`
diff --git a/setup.py b/setup.py
index 96289c1..60fe6da 100644
--- a/setup.py
+++ b/setup.py
@@ -37,9 +37,9 @@
       license='MIT',
       packages=['vecstack'],
       install_requires=[
-          'numpy',
-          'scipy',
-          'scikit-learn>=0.18'
+          'numpy<1.17',
+          'scipy<1.3',
+          'scikit-learn>=0.18,<0.21'
       ],
       test_suite='nose.collector',
       tests_require=['nose'],