diff --git a/code/requirements.txt b/code/requirements.txt
index ad63fef..6373dd9 100644
--- a/code/requirements.txt
+++ b/code/requirements.txt
@@ -72,7 +72,7 @@ lazy-object-proxy==1.3.1
 llvmlite==0.20.0
 locket==0.2.0
 lockfile==0.12.2
-lxml==3.8.0
+lxml==4.6.2
 MarkupSafe==1.0
 matplotlib==2.0.2
 mccabe==0.6.1
diff --git a/requirements.txt b/requirements.txt
index d72027e..cdca10f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -73,7 +73,7 @@ lazy-object-proxy==1.3.1
 llvmlite==0.20.0
 locket==0.2.0
 lockfile==0.12.2
-lxml==3.8.0
+lxml==4.6.2
 MarkupSafe==1.0
 matplotlib==2.0.2
 mccabe==0.6.1
diff --git a/submission/requirements.txt b/submission/requirements.txt
index 8480463..da433cb 100644
--- a/submission/requirements.txt
+++ b/submission/requirements.txt
@@ -73,7 +73,7 @@ lazy-object-proxy==1.3.1
 llvmlite==0.20.0
 locket==0.2.0
 lockfile==0.12.2
-lxml==3.8.0
+lxml==4.6.2
 MarkupSafe==1.0
 matplotlib==2.0.2
 mccabe==0.6.1