diff --git a/cnitool/cnitool.go b/cnitool/cnitool.go
index b2685bce..20ffcf12 100644
--- a/cnitool/cnitool.go
+++ b/cnitool/cnitool.go
@@ -34,8 +34,6 @@ const (
 	EnvCNIArgs        = "CNI_ARGS"
 	EnvCNIIfname      = "CNI_IFNAME"
 
-	DefaultNetDir = "/etc/cni/net.d"
-
 	CmdAdd   = "add"
 	CmdCheck = "check"
 	CmdDel   = "del"
diff --git a/cnitool/constants_unix.go b/cnitool/constants_unix.go
new file mode 100644
index 00000000..dda0a500
--- /dev/null
+++ b/cnitool/constants_unix.go
@@ -0,0 +1,22 @@
+// Copyright 2023 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package main
+
+const (
+	DefaultNetDir = "/etc/cni/net.d"
+)
diff --git a/cnitool/constants_windows.go b/cnitool/constants_windows.go
new file mode 100644
index 00000000..d14d3e14
--- /dev/null
+++ b/cnitool/constants_windows.go
@@ -0,0 +1,22 @@
+// Copyright 2023 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+const (
+	// NOTE: this is the most reasonable default as most CNI setups on Windows
+	// will have been made using the helper script in the containerd repo.
+	// https://github.com/containerd/containerd/blob/main/script/setup/install-cni-windows
+	DefaultNetDir = "C:\\Program Files\\containerd\\cni\\conf"
+)