diff --git a/requirements.python2.txt b/requirements.python2.txt
index 7fbbdc6..2a038ec 100644
--- a/requirements.python2.txt
+++ b/requirements.python2.txt
@@ -8,7 +8,7 @@ Pillow==6.0.0
 protobuf==3.7.1
 pytest==4.5.0
 pytest-cov==2.7.1
-PyYAML==5.1
+PyYAML==5.4
 scipy==1.1.0
 setproctitle==1.1.10
 six==1.12.0
diff --git a/requirements.txt b/requirements.txt
index 2117f41..7f13b79 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,7 +10,7 @@ psutil==5.6.2
 pytest==4.5.0
 # pytest==3.9.1 # strange... Python 3.7.0 sometimes donot work with pytest==4.5.0; can use 3.9.1
 pytest-cov==2.7.1
-PyYAML==5.1
+PyYAML==5.4
 scipy==1.3.0rc1 # Python >= 3.5 required
 setproctitle==1.1.10
 six==1.12.0