diff --git a/pa/genetic_algorithm/R1/requirements.txt b/pa/genetic_algorithm/R1/requirements.txt
index f826ca6..0c45e1f 100644
--- a/pa/genetic_algorithm/R1/requirements.txt
+++ b/pa/genetic_algorithm/R1/requirements.txt
@@ -13,7 +13,7 @@ MarkupSafe==1.0
 pipreqs==0.4.9
 pymongo==3.7.1
 pytz==2018.5
-PyYAML==3.13
+PyYAML==5.1
 requests==2.19.1
 six==1.11.0
 urllib3==1.23
diff --git a/pa/genetic_algorithm/R2/requirements.txt b/pa/genetic_algorithm/R2/requirements.txt
index c700c50..5c3c0a5 100644
--- a/pa/genetic_algorithm/R2/requirements.txt
+++ b/pa/genetic_algorithm/R2/requirements.txt
@@ -15,7 +15,7 @@ MarkupSafe==1.0
 pipreqs==0.4.9
 pymongo==3.7.1
 pytz==2018.5
-PyYAML==3.13
+PyYAML==5.1
 requests==2.19.1
 six==1.11.0
 urllib3==1.23
diff --git a/pa/genetic_algorithm/requirements.txt b/pa/genetic_algorithm/requirements.txt
index f826ca6..0c45e1f 100644
--- a/pa/genetic_algorithm/requirements.txt
+++ b/pa/genetic_algorithm/requirements.txt
@@ -13,7 +13,7 @@ MarkupSafe==1.0
 pipreqs==0.4.9
 pymongo==3.7.1
 pytz==2018.5
-PyYAML==3.13
+PyYAML==5.1
 requests==2.19.1
 six==1.11.0
 urllib3==1.23