diff --git a/bitbake/lib/prserv/db.py b/bitbake/lib/prserv/db.py
index b7190bad01..3fb2c3482a 100644
--- a/bitbake/lib/prserv/db.py
+++ b/bitbake/lib/prserv/db.py
@@ -224,7 +224,7 @@ class PRData(object):
         except OSError as e:
             if e.errno != errno.EEXIST:
                 raise e
-        self.connection=sqlite3.connect(self.filename, isolation_level="DEFERRED", check_same_thread = False)
+        self.connection=sqlite3.connect(self.filename, isolation_level="EXCLUSIVE", check_same_thread = False)
         self.connection.row_factory=sqlite3.Row
         self._tables={}