diff --git a/windows/syscall_windows_test.go b/windows/syscall_windows_test.go
index 0f73c11b..9c7133cc 100644
--- a/windows/syscall_windows_test.go
+++ b/windows/syscall_windows_test.go
@@ -81,7 +81,7 @@ func TestFormatMessage(t *testing.T) {
 	buf := make([]uint16, 300)
 	_, err = windows.FormatMessage(flags, uintptr(dll.Handle), uint32(errno), 0, buf, nil)
 	if err != nil {
-		t.Fatal("FormatMessage for handle=%x and errno=%x failed: %v", dll.Handle, errno, err)
+		t.Fatalf("FormatMessage for handle=%x and errno=%x failed: %v", dll.Handle, errno, err)
 	}
 }