diff --git a/pyproject.toml b/pyproject.toml
index 4561abaf4..54755da48 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,7 +54,8 @@ dependencies = [
 [project.optional-dependencies]
 default = []
 curl-cffi = [
-    "curl-cffi>=0.5.10,!=0.6.*,<0.8; implementation_name=='cpython'",
+    "curl-cffi==0.5.10; os_name=='nt' and implementation_name=='cpython'",
+    "curl-cffi>=0.5.10,!=0.6.*,<0.8; os_name!='nt' and implementation_name=='cpython'",
 ]
 secretstorage = [
     "cffi",