diff --git a/internal/output/file.go b/internal/output/file.go
index ec45027..bd5f7e7 100644
--- a/internal/output/file.go
+++ b/internal/output/file.go
@@ -36,7 +36,10 @@ func CreateFile(path string) (*File, error) {
 	keep := os.FileMode(0)
 	if fi, err := os.Stat(path); err == nil {
 		if !fi.Mode().IsRegular() {
-			f, err := os.OpenFile(path, os.O_WRONLY|os.O_TRUNC, 0)
+			// No O_TRUNC: truncating a device or pipe is meaningless, and
+			// Windows rejects it on the NUL device with ERROR_INVALID_FUNCTION
+			// (#208), which broke -o NUL.
+			f, err := os.OpenFile(path, os.O_WRONLY, 0)
 			if err != nil {
 				return nil, err
 			}
diff --git a/internal/output/lifecycle_test.go b/internal/output/lifecycle_test.go
index 413b881..a2b50d0 100644
--- a/internal/output/lifecycle_test.go
+++ b/internal/output/lifecycle_test.go
@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"os"
 	"path/filepath"
-	"runtime"
 	"strings"
 	"testing"
 
@@ -97,9 +96,6 @@ func TestCreateFileMissingDirectory(t *testing.T) {
 }
 
 func TestCreateFileWritesNonRegularTargetDirectly(t *testing.T) {
-	if runtime.GOOS == "windows" {
-		t.Skip("opening NUL with O_TRUNC fails on Windows")
-	}
 	fi, err := os.Stat(os.DevNull)
 	if err != nil || fi.Mode().IsRegular() {
 		t.Skipf("%s is not a device here", os.DevNull)