diff --git a/patroni/postgresql/config.py b/patroni/postgresql/config.py
index c6ed5ce3..e80505b1 100644
--- a/patroni/postgresql/config.py
+++ b/patroni/postgresql/config.py
@@ -614,6 +614,7 @@ class ConfigHandler(object):
                 values[match.group(1)] = [value, True]
             self._recovery_conf_mtime = recovery_conf_mtime
         values.setdefault('recovery_min_apply_delay', ['0', True])
+        values['recovery_min_apply_delay'][0] = parse_int(values['recovery_min_apply_delay'][0], 'ms')
         values.update({param: ['', True] for param in self._recovery_parameters_to_compare if param not in values})
         return values, True