diff --git a/requirements_py3_matteo.txt b/requirements_py3_matteo.txt
index e962deb..c323f04 100644
--- a/requirements_py3_matteo.txt
+++ b/requirements_py3_matteo.txt
@@ -44,7 +44,7 @@ jupyter-client==4.4.0
 jupyter-core==4.2.1
 lazy-object-proxy==1.2.2
 leather==0.3.3
-lxml==3.7.2
+lxml==4.6.3
 MarkupSafe==0.23
 matplotlib==2.0.0
 mccabe==0.6.1
diff --git a/requirements_py3_refactored.txt b/requirements_py3_refactored.txt
old mode 100755
new mode 100644
index a5d4d22..f9cefed
--- a/requirements_py3_refactored.txt
+++ b/requirements_py3_refactored.txt
@@ -63,7 +63,7 @@ jupyter-core==4.4.0
 lazy-object-proxy==1.2.2
 leather==0.3.3
 locket==0.2.0
-lxml==3.7.2
+lxml==4.6.3
 MarkupSafe==1.0
 matplotlib==2.0.0
 mccabe==0.6.1