diff --git a/mongodb_consistent_backup/Replication/Replset.py b/mongodb_consistent_backup/Replication/Replset.py
index 72e1689b..408053af 100644
--- a/mongodb_consistent_backup/Replication/Replset.py
+++ b/mongodb_consistent_backup/Replication/Replset.py
@@ -17,8 +17,11 @@ def __init__(self, config, db):
         self.max_priority = self.config.replication.max_priority
         self.hidden_only  = self.config.replication.hidden_only
 
-        self.hidden_weight = 0.20
-        self.pri0_weight   = 0.10
+        self.state_primary   = 1
+        self.state_secondary = 2
+        self.state_arbiter   = 7
+        self.hidden_weight   = 0.20
+        self.pri0_weight     = 0.10
 
         self.replset      = True
         self.rs_config    = None
@@ -144,7 +147,7 @@ def find_primary(self, force=False, quiet=False):
             rs_status = self.get_rs_status(force, quiet)
             rs_name   = rs_status['set']
             for member in rs_status['members']:
-                if member['stateStr'] == 'PRIMARY' and member['health'] > 0:
+                if member['state'] == self.state_primary and member['health'] > 0:
                     member_uri = MongoUri(member['name'], 27017, rs_name)
                     optime_ts  = member['optime']
                     if isinstance(member['optime'], dict) and 'ts' in member['optime']:
@@ -184,14 +187,14 @@ def find_secondary(self, force=False, quiet=False):
             if self.is_member_electable(member_config):
                 electable_count += 1
 
-            if member['state'] == 7:
+            if member['state'] == self.state_arbiter:
                 logging.info("Found ARBITER %s, skipping" % member_uri)
-            elif member['state'] > 2:
+            elif member['state'] > self.state_secondary:
                 logging.warning("Found down or unhealthy SECONDARY %s with state: %s" % (member_uri, member['stateStr']))
-            elif member['state'] == 2 and member['health'] > 0:
+            elif member['state'] == self.state_secondary and member['health'] > 0:
                 log_data    = {}
                 score       = self.max_lag_secs * 10
-                score_scale = 100 / score
+                score_scale = 100.00 / float(score)
                 priority    = 0
                 if 'hidden' in member_config and member_config['hidden']:
                     score += (score * self.hidden_weight)
@@ -224,6 +227,10 @@ def find_secondary(self, force=False, quiet=False):
                 else:
                     log_msg = "Found SECONDARY %s with too high replication lag! Skipping" % member_uri
 
+                if self.secondary['score'] == 0:
+                    logging.error("Chosen SECONDARY %s has a score of zero/0! This is unexpected, exiting" % member_uri)
+                    raise OperationError("Chosen SECONDARY %s has a score of zero/0!" % member_uri)
+
                 if 'configsvr' in rs_status and rs_status['configsvr']:
                     log_data['configsvr'] = True