diff --git a/requirements.txt b/requirements.txt
index 959efe64d..5bf176d28 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,4 +7,3 @@ scipy==1.4.1; platform_python_implementation != "PyPy"
 munkres==1.1.2; platform_python_implementation == "PyPy"
 zopfli==0.1.6
 fs==2.4.11
-lxml==4.5.0
diff --git a/tox.ini b/tox.ini
index 033e13863..c160e8b4f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,6 +10,7 @@ deps =
     pytest
     pytest-randomly
     -rrequirements.txt
+    !nolxml: lxml==4.5.0
 extras =
     ufo
     woff