diff --git a/tox.ini b/tox.ini
index 06abda3..8a524c4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -130,7 +130,6 @@ setenv =
 setenv =
     PYTHONDEVMODE=1
     PIP_DISABLE_PIP_VERSION_CHECK=1
-    UNSAFE_PYO3_SKIP_VERSION_CHECK=1
 
 [testenv:py312]
 setenv =
@@ -305,19 +304,16 @@ setenv =
 setenv =
     PYTHONDEVMODE=1
     PIP_DISABLE_PIP_VERSION_CHECK=1
-    UNSAFE_PYO3_SKIP_VERSION_CHECK=1
 
 [testenv:py313-dev-mypy{0.900,0.910,0.921,0.931,1.0.1,1.2.0,1.4.1,1.6.1,latest}]
 setenv =
     PYTHONDEVMODE=1
     PIP_DISABLE_PIP_VERSION_CHECK=1
-    UNSAFE_PYO3_SKIP_VERSION_CHECK=1
 
 [testenv:py313-dev-sphinx{4,5,6,7}]
 setenv =
     PYTHONDEVMODE=1
     PIP_DISABLE_PIP_VERSION_CHECK=1
-    UNSAFE_PYO3_SKIP_VERSION_CHECK=1
 
 [testenv:py312-mypy{0.900,0.910,0.921,0.931,1.0.1,1.2.0,1.4.1,1.6.1,1.8.0,latest}]
 setenv =