diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index 0a177c6..f7d6c6f 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -664,6 +664,7 @@
             f.write(tail)
             f.flush()
         except (IOError, OverflowError):
+            f.close()
             raise unittest.SkipTest("filesystem does not have largefile support")
         return f