diff --git a/requirements/conversion.txt b/requirements/conversion.txt
index 1f96b8e..b1b0a75 100644
--- a/requirements/conversion.txt
+++ b/requirements/conversion.txt
@@ -8,5 +8,5 @@ coloredlogs==7.0
     # via -r conversion.in
 humanfriendly==3.8
     # via coloredlogs
-lxml==4.6.3
+lxml==4.9.1
     # via -r conversion.in
diff --git a/requirements/deploy.txt b/requirements/deploy.txt
index ef70de1..c34ceb4 100644
--- a/requirements/deploy.txt
+++ b/requirements/deploy.txt
@@ -8,7 +8,7 @@ coloredlogs==7.0
     # via -r conversion.in
 humanfriendly==3.8
     # via coloredlogs
-lxml==4.6.3
+lxml==4.9.1
     # via -r conversion.in
 numpy==1.13.1
     # via -r selection.in
diff --git a/requirements/develop.txt b/requirements/develop.txt
index 4ff939e..c287cc4 100644
--- a/requirements/develop.txt
+++ b/requirements/develop.txt
@@ -16,7 +16,7 @@ isort==4.2.15
     # via pylint
 lazy-object-proxy==1.3.1
     # via astroid
-lxml==4.6.3
+lxml==4.9.1
     # via -r conversion.in
 mccabe==0.6.1
     # via pylint