diff --git a/acts/framework/setup.py b/acts/framework/setup.py
index 6eb41e1..e527a21 100755
--- a/acts/framework/setup.py
+++ b/acts/framework/setup.py
@@ -29,7 +29,8 @@
     # Latest version of mock (4.0.0b) causes a number of compatibility issues with ACTS unit tests
     # b/148695846, b/148814743
     'mock==3.0.5',
-    'numpy',
+    # b/157117302: python3.5 is not supported by NumPy 1.19+
+    'numpy<=1.18.1',
     'pyserial',
     'pyyaml>=5.1',
     'tzlocal',