diff --git a/requirements.txt b/requirements.txt
index 28d449c..9e0cda6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,7 +16,7 @@ matplotlib == 3.2.2
 numpy == 1.19.2
 
 # pysbpl/pysbpl/map_util.py: 3
-opencv_contrib_python == 3.4.0.12
+opencv_contrib_python == 3.4.7.28
 
 # pysbpl/setup.py: 1
 setuptools == 20.7.0