diff --git a/Makefile b/Makefile
index 3c30854f..7f13efee 100644
--- a/Makefile
+++ b/Makefile
@@ -13,3 +13,5 @@ upload:
 clean:
 	rm -rf dist
 	rm -rf build
+
+.NOTPARALLEL:
diff --git a/requirements.txt b/requirements.txt
index 9d677fda..519f4f84 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,6 +5,6 @@ matplotlib
 joblib
 tqdm
 pygame
-opencv-python
+opencv-python>=4.7
 torch
 pytest