diff --git a/src/ldaptools/slapd.py b/src/ldaptools/slapd.py
index f0e30bb..41ba770 100644
--- a/src/ldaptools/slapd.py
+++ b/src/ldaptools/slapd.py
@@ -93,9 +93,12 @@ olcAccess: {{0}}to *
     process = None
     schemas = ['core', 'cosine', 'inetorgperson', 'nis', 'eduorg-200210-openldap', 'eduperson',
                'supann-2009']
-    schemas_ldif = [codecs.open(os.path.join(os.path.dirname(__file__),
-                                      'schemas', '%s.ldif' % schema),
-                                      encoding='utf-8').read() for schema in schemas]
+    schemas_ldif = []
+    for schema in schemas:
+        with codecs.open(
+                os.path.join(
+                    os.path.dirname(__file__), 'schemas', '%s.ldif' % schema), encoding='utf-8') as fd:
+            schemas_ldif.append(fd.read())
     checkpoints = None
     data_dirs = None
     db_index = 1