diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index a87e6ae..2c2863e 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -655,6 +655,7 @@
             f.write(tail)
             f.flush()
         except (IOError, OverflowError):
+            f.close()
             raise unittest.SkipTest("filesystem does not have largefile support")
         return f