diff --git a/tests/TemporaryFile.h b/tests/TemporaryFile.h
index a7b13b0..c4ee2d5 100644
--- a/tests/TemporaryFile.h
+++ b/tests/TemporaryFile.h
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <fcntl.h>
 #include <unistd.h>
 
 template<int (*mk_fn)(char*)>
@@ -39,6 +40,11 @@
     unlink(filename);
   }
 
+  void reopen() {
+    close(fd);
+    fd = open(filename, O_RDWR);
+  }
+
   int fd;
   char filename[1024];