diff --git a/tox.ini b/tox.ini
index dc2756ab49a..0dd0ec8610c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -72,9 +72,24 @@ isolated_build = true
 
 requires = virtualenv<=20.2.1
 
-[testenv]
+[testenv:gevent_contrib-py{37,38}-gevent{13,14}-sslmodules3-sslmodules]
+# Wheels for gevent segfault pretty easily
+install_command=python -m pip install --no-binary=gevent {opts} {packages}
+usedevelop = true
+
+[testenv:py{37,38}-opentracer_gevent-gevent{13,14}]
 # Wheels for gevent segfault pretty easily
-install_command=python -m pip install --no-binary gevent {opts} {packages}
+install_command=python -m pip install --no-binary=gevent {opts} {packages}
+usedevelop = true
+
+[testenv:py{37,38}-profile-minreqs-gevent]
+# Wheels for gevent segfault pretty easily
+install_command=python -m pip install --no-binary=gevent {opts} {packages}
+usedevelop = true
+
+
+[testenv]
+install_command=python -m pip install {opts} {packages}
 usedevelop = true
 
 setenv =
@@ -86,7 +101,7 @@ extras =
   profile: profiling
 
 deps =
-    cython
+    cython<=0.29.32
     cmake
     ninja
     pytest-cov
@@ -104,8 +119,10 @@ deps =
     profile-!minreqs-gevent: gevent
     py27-profile-minreqs-gevent: gevent==1.1.0
     py{35,36,37,38}-profile-minreqs-gevent: gevent==1.4.0
-    py39-profile-minreqs-gevent: gevent==20.6.0
-    py39-profile-minreqs-gevent: greenlet==0.4.16
+    py39-profile-minreqs-gevent: gevent==20.6.1; sys_platform != 'win32'
+    py39-profile-minreqs-gevent: gevent==21.1.2; sys_platform == 'win32'
+    py39-profile-minreqs-gevent: greenlet==0.4.16; sys_platform != 'win32'
+    py39-profile-minreqs-gevent: greenlet==0.4.17; sys_platform == 'win32'
     py310-profile-minreqs-gevent: gevent==21.8.0
     py310-profile-minreqs-gevent: greenlet==1.1.0
 # backports