diff --git a/pyfasta/records.py b/pyfasta/records.py
index f352b1e..8f6f2b1 100644
--- a/pyfasta/records.py
+++ b/pyfasta/records.py
@@ -85,9 +85,8 @@ def copy_inplace(klass, flat_name, fasta_name):
         os.rename(flat_name, fasta_name)
         # still need the flattend file to show
         # it's current.
-        flatfh = open(fasta_name + klass.ext, 'w')
-        flatfh.write(MAGIC)
-        flatfh.close()
+        with open(fasta_name + klass.ext, 'w') as flatfh:
+            flatfh.write(MAGIC)