diff --git a/requirements.txt b/requirements.txt
index f1a4a87..5842fdd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,7 +6,7 @@ Sphinx==3.2.1
 rinohtype
 importlib_metadata
 ipykernel
-numpy
+numpy~=1.19.2
 matplotlib==3.3.1
 cantools>=32.20.1
 libusb1>=1.7.1