diff --git a/pkg/controller/perconaservermongodb/mgo.go b/pkg/controller/perconaservermongodb/mgo.go
index e9c5d032b3..03f83b83f1 100644
--- a/pkg/controller/perconaservermongodb/mgo.go
+++ b/pkg/controller/perconaservermongodb/mgo.go
@@ -376,14 +376,8 @@ func (r *ReconcilePerconaServerMongoDB) getConfigMemberForExternalNode(id int, e
 func (r *ReconcilePerconaServerMongoDB) updateConfigMembers(ctx context.Context, cli mongo.Client, cr *api.PerconaServerMongoDB, rs *api.ReplsetSpec) (map[string]api.ReplsetMemberStatus, int, error) {
 	log := logf.FromContext(ctx)
 	// Primary with a Secondary and an Arbiter (PSA)
-	unsafePSA := false
 	rsMembers := make(map[string]api.ReplsetMemberStatus)
-
-	if cr.CompareVersion("1.15.0") <= 0 {
-		unsafePSA = cr.Spec.UnsafeConf && rs.Arbiter.Enabled && rs.Arbiter.Size == 1 && !rs.NonVoting.Enabled && rs.Size == 2
-	} else {
-		unsafePSA = cr.Spec.Unsafe.ReplsetSize && rs.Arbiter.Enabled && rs.Arbiter.Size == 1 && !rs.NonVoting.Enabled && rs.Size == 2
-	}
+	unsafePSA := cr.Spec.Unsafe.ReplsetSize && rs.Arbiter.Enabled && rs.Arbiter.Size == 1 && !rs.NonVoting.Enabled && rs.Size == 2
 
 	pods, err := psmdb.GetRSPods(ctx, r.client, cr, rs.Name)
 	if err != nil {
@@ -470,13 +464,20 @@ func (r *ReconcilePerconaServerMongoDB) updateConfigMembers(ctx context.Context,
 		}
 	}
 
-	if cnf.Members.AddNew(ctx, members) {
+	if cnf.Members.RemoveArbiterIfNeeded(ctx, unsafePSA) {
+		cnf.Version++
+
+		log.Info("Removing arbiter members", "replset", rs.Name)
+
+		if err := cli.WriteConfig(ctx, cnf, false); err != nil {
+			return rsMembers, 0, errors.Wrap(err, "remove arbiter if needed: write mongo config")
+		}
+	} else if cnf.Members.AddNew(ctx, members) {
 		cnf.Version++
 
 		log.Info("Adding new nodes", "replset", rs.Name)
 
-		err = cli.WriteConfig(ctx, cnf, false)
-		if err != nil {
+		if err := cli.WriteConfig(ctx, cnf, false); err != nil {
 			return rsMembers, 0, errors.Wrap(err, "add new: write mongo config")
 		}
 	}
diff --git a/pkg/psmdb/mongo/mongo.go b/pkg/psmdb/mongo/mongo.go
index f524b8b34e..f84939b265 100644
--- a/pkg/psmdb/mongo/mongo.go
+++ b/pkg/psmdb/mongo/mongo.go
@@ -260,7 +260,6 @@ func (client *mongoClient) UpdateRole(ctx context.Context, db string, role Role)
 	}
 
 	return nil
-
 }
 
 func (client *mongoClient) GetRole(ctx context.Context, db, role string) (*Role, error) {
@@ -901,6 +900,37 @@ func (m *ConfigMembers) AddNew(ctx context.Context, from ConfigMembers) bool {
 	return false
 }
 
+func (m *ConfigMembers) RemoveArbiterIfNeeded(ctx context.Context, unsafePSA bool) bool {
+	if !unsafePSA {
+		return false
+	}
+
+	votingMembers := 0
+	hasArbiter := false
+	for _, member := range *m {
+		if member.ArbiterOnly {
+			hasArbiter = true
+			continue
+		}
+		if member.Votes > 0 {
+			votingMembers++
+		}
+	}
+	if !hasArbiter || votingMembers > 1 {
+		return false
+	}
+	log := logf.FromContext(ctx)
+
+	for i := len(*m) - 1; i >= 0 && len(*m) > 1; i-- {
+		member := []ConfigMember(*m)[i]
+		if member.ArbiterOnly {
+			log.Info("Removing arbiter member because of 1 writable node", "_id", member.ID, "host", member.Host)
+			*m = append([]ConfigMember(*m)[:i], []ConfigMember(*m)[i+1:]...)
+		}
+	}
+	return true
+}
+
 func (m *ConfigMembers) setMemberVoteAndPriority(i int, votes, priority int) {
 	(*m)[i].Votes = votes
 	(*m)[i].Priority = priority
@@ -990,7 +1020,7 @@ func (m *ConfigMembers) SetVotes(compareWith ConfigMembers, unsafePSA bool) {
 		return
 	}
 
-	if votes%2 == 0 {
+	if votes%2 == 0 && !unsafePSA {
 		for j := lastVoteIdx; j >= 0; j-- {
 			if []ConfigMember(*m)[j].Votes == 0 {
 				continue
diff --git a/pkg/psmdb/mongo/mongo_test.go b/pkg/psmdb/mongo/mongo_test.go
index b485fc8f3c..0495b5c1c3 100644
--- a/pkg/psmdb/mongo/mongo_test.go
+++ b/pkg/psmdb/mongo/mongo_test.go
@@ -209,6 +209,32 @@ func TestVoting(t *testing.T) {
 			},
 			true,
 		},
+		{
+			"2 members (unsafe PSA start): 2 rs0 without arbiter",
+			&mongo.ConfigMembers{
+				mongo.ConfigMember{
+					Host:     "host0",
+					Votes:    mongo.DefaultVotes,
+					Priority: mongo.DefaultPriority,
+				},
+				mongo.ConfigMember{
+					Host:     "host1",
+					Votes:    mongo.DefaultVotes,
+					Priority: mongo.DefaultPriority,
+				},
+			},
+			&mongo.ConfigMembers{
+				mongo.ConfigMember{
+					Votes:    mongo.DefaultVotes,
+					Priority: mongo.DefaultPriority,
+				},
+				mongo.ConfigMember{
+					Votes:    mongo.DefaultVotes,
+					Priority: mongo.DefaultPriority,
+				},
+			},
+			true,
+		},
 		{
 			"4 members: 4 rs0",
 			&mongo.ConfigMembers{
@@ -1297,7 +1323,7 @@ func TestVoting(t *testing.T) {
 			}
 
 			assert.Falsef(t, votes > mongo.MaxVotingMembers, "there should be max (%d) votes in replset", mongo.MaxVotingMembers)
-			if votes != 0 {
+			if votes != 0 && !c.unsafePSA {
 				assert.Falsef(t, votes%2 == 0, "total votes (%d) should be an odd number", votes)
 			}
 		})