diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index dc975a9d..54af176f 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,8 +8,7 @@ jobs:
     strategy:
       matrix:
         go-version: [1.16.x,1.17.x,1.18.x]
-        # TODO(bep) fix windows-latest
-        platform: [ubuntu-latest, macos-latest]
+        platform: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.platform }}
     steps:
     - name: Install Go
@@ -25,10 +24,10 @@ jobs:
       shell: bash
     - name: Checkout code
       uses: actions/checkout@v1
-    #- name: Fmt
-    #  if: matrix.platform != 'windows-latest' # :(
-    #  run: "diff <(gofmt -d .) <(printf '')"
-    #  shell: bash
+    - name: Fmt
+      if: matrix.platform != 'windows-latest' # :(
+      run: "diff <(gofmt -d .) <(printf '')"
+      shell: bash
     - name: Vet
       run: go vet ./...
     #- name: Staticcheck
diff --git a/iofs_test.go b/iofs_test.go
index 7ae73c7b..4264c65c 100644
--- a/iofs_test.go
+++ b/iofs_test.go
@@ -9,6 +9,7 @@ import (
 	"io"
 	"io/fs"
 	"os"
+	"path/filepath"
 	"testing"
 	"testing/fstest"
 	"time"
@@ -20,19 +21,19 @@ func TestIOFS(t *testing.T) {
 	t.Run("use MemMapFs", func(t *testing.T) {
 		mmfs := NewMemMapFs()
 
-		err := mmfs.MkdirAll("dir1/dir2", os.ModePerm)
+		err := mmfs.MkdirAll(filepath.FromSlash("dir1/dir2"), os.ModePerm)
 		if err != nil {
 			t.Fatal("MkdirAll failed:", err)
 		}
 
-		f, err := mmfs.OpenFile("dir1/dir2/test.txt", os.O_RDWR|os.O_CREATE, os.ModePerm)
+		f, err := mmfs.OpenFile(filepath.FromSlash("dir1/dir2/test.txt"), os.O_RDWR|os.O_CREATE, os.ModePerm)
 		if err != nil {
 			t.Fatal("OpenFile (O_CREATE) failed:", err)
 		}
 
 		f.Close()
 
-		if err := fstest.TestFS(NewIOFS(mmfs), "dir1/dir2/test.txt"); err != nil {
+		if err := fstest.TestFS(NewIOFS(mmfs), filepath.FromSlash("dir1/dir2/test.txt")); err != nil {
 			t.Error(err)
 		}
 	})
@@ -40,19 +41,19 @@ func TestIOFS(t *testing.T) {
 	t.Run("use OsFs", func(t *testing.T) {
 		osfs := NewBasePathFs(NewOsFs(), t.TempDir())
 
-		err := osfs.MkdirAll("dir1/dir2", os.ModePerm)
+		err := osfs.MkdirAll(filepath.FromSlash("dir1/dir2"), os.ModePerm)
 		if err != nil {
 			t.Fatal("MkdirAll failed:", err)
 		}
 
-		f, err := osfs.OpenFile("dir1/dir2/test.txt", os.O_RDWR|os.O_CREATE, os.ModePerm)
+		f, err := osfs.OpenFile(filepath.FromSlash("dir1/dir2/test.txt"), os.O_RDWR|os.O_CREATE, os.ModePerm)
 		if err != nil {
 			t.Fatal("OpenFile (O_CREATE) failed:", err)
 		}
 
 		f.Close()
 
-		if err := fstest.TestFS(NewIOFS(osfs), "dir1/dir2/test.txt"); err != nil {
+		if err := fstest.TestFS(NewIOFS(osfs), filepath.FromSlash("dir1/dir2/test.txt")); err != nil {
 			t.Error(err)
 		}
 	})