diff --git a/pyproject.toml b/pyproject.toml
index 23aea73ed9..37c4338b0c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,7 +30,7 @@ requires-python = ">=3.8"
 dependencies = [
     'certifi',
     'isodate==0.*',
-    'lxml==4.*',
+    'lxml>=4,<7',
     'numpy==1.*',
     'openpyxl==3.*',
     'pyparsing==3.*',
diff --git a/requirements.txt b/requirements.txt
index 0d40b16342..9e20d3650e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 # core modules
 certifi==2023.7.22
-lxml==4.9.3
+lxml==6.1.0
 OpenPyXL==3.1.2
 pyparsing==3.0.9
 regex==2023.6.3