diff --git a/setup.cfg b/setup.cfg
index 47ae6183af..e1702046ba 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -42,7 +42,7 @@ install_requires =
     terminado>=0.8.3
     prometheus_client
     pywin32>=1.0 ; sys_platform == 'win32'
-    anyio>=3.0<4
+    anyio>=3.0,<4
 
 [options.extras_require]
 test = coverage; pytest; pytest-cov; pytest-mock; requests; pytest-tornasync; pytest-console-scripts; ipykernel