diff --git a/pyproject.toml b/pyproject.toml
index d4c93442..740009c3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -79,9 +79,7 @@ google-onetap = [
   "google-auth~=2.38.0"
 ]
 saml = [
-  "python3-saml>=1.5.0",
-  # pinned to 5.2 until a new wheel of xmlsec is released
-  "lxml~=5.2.1"
+  "python3-saml>=1.5.0"
 ]
 shopify = [
   "ShopifyAPI"
diff --git a/tox.ini b/tox.ini
index 86b01f87..4c9037eb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,6 +8,7 @@ envlist = py39,py310,py311,py312,py313,py39-pyright,p313-pyright
 
 [testenv]
 passenv = *
+install_command = python -I -m pip install --no-binary lxml --no-binary xmlsec {opts} {packages}
 deps =
   py{39,310,311,312,313}: -e .[dev,all]
 commands =