diff --git a/Pipfile b/Pipfile
index d428d9d..bb2458f 100644
--- a/Pipfile
+++ b/Pipfile
@@ -9,6 +9,8 @@ qrcode = "*"
 pillow = "*"
 qreader = "*"
 opencv-python = "*"
+# for macOS: opencv-python = "<=4.7.0"
+# for PYTHON <= 3.7: typing_extensions = "*"
 
 [dev-packages]
 pytest = "*"
diff --git a/requirements.txt b/requirements.txt
index 4bfe3b5..ee7e531 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,6 +2,7 @@ protobuf
 qrcode
 Pillow
 qreader
-opencv-python
+opencv-python<=4.7.0; sys_platform == 'darwin'
+opencv-python; sys_platform != 'darwin'
 pyzbar
-typing_extensions  # PYTHON < 3.11: add types
+typing_extensions; python_version<='3.7'