diff --git a/gramps/plugins/importer/importprogen.py b/gramps/plugins/importer/importprogen.py
index 095996d3c..6279f8021 100644
--- a/gramps/plugins/importer/importprogen.py
+++ b/gramps/plugins/importer/importprogen.py
@@ -462,7 +462,9 @@ class PG30_Def:
 
         # This can throw a IOError
         import io
-        lines = io.open(fname, buffering=1, encoding='cp437', errors='strict').readlines()
+        lines = None
+        with f = io.open(fname, buffering=1, encoding='cp437', errors='strict'):
+            lines = f.readlines()
         lines = [l.strip() for l in lines]
         content = '\n'.join(lines).encode('utf-8')
         parts = re.split(r'\n(?=\[)', content)