diff --git a/command-sub.go b/command-sub.go
index 531dcaa..73bf462 100644
--- a/command-sub.go
+++ b/command-sub.go
@@ -15,7 +15,10 @@ package main
 
 import (
 	"encoding/json"
+	"log"
 	"os"
+	"strconv"
+	"time"
 
 	"github.com/spf13/cobra"
 )
@@ -52,7 +55,101 @@ func newSubCommand() *cobra.Command {
 }
 
 func (c *subCommand) run(_ *cobra.Command, _ []string) {
-	total := runSubWithPubret(c.subscribers, c.repeat, c.expectRetained, c.expectPublished, c.messageOpts, false)
+	total := runSubPrepublishRetained(c.subscribers, c.repeat, c.expectRetained, c.expectPublished, c.messageOpts, false)
 	bb, _ := json.Marshal(total)
 	os.Stdout.Write(bb)
 }
+
+func runSubPrepublishRetained(
+	nSubscribers int,
+	repeat int,
+	expectRetained,
+	expectPublished int,
+	messageOpts messageOpts,
+	prepublishRetained bool,
+) *Stat {
+	errCh := make(chan error)
+	receiverReadyCh := make(chan struct{})
+	statsCh := make(chan *Stat)
+
+	if prepublishRetained {
+		if expectPublished != 0 {
+			log.Fatalf("Error: --messages is not supported with --retained")
+		}
+
+		// We need to wait for all prepublished retained messages to be processed.
+		// To ensure, subscribe once before we pre-publish and receive all published
+		// messages.
+		r := &receiver{
+			clientID:        ClientID + "-sub-init",
+			filterPrefix:    messageOpts.topic,
+			topic:           messageOpts.topic + "/+",
+			qos:             messageOpts.qos,
+			expectRetained:  0,
+			expectPublished: expectRetained,
+			repeat:          1,
+		}
+		go r.receive(receiverReadyCh, statsCh, errCh)
+		<-receiverReadyCh
+
+		// Pre-publish retained messages.
+		p := &publisher{
+			clientID:    ClientID + "-pub",
+			messages:    expectRetained,
+			topics:      expectRetained,
+			messageOpts: messageOpts,
+		}
+		p.messageOpts.retain = true
+		go p.publish(nil, errCh, true)
+
+		// wait for the initial subscription to have received all messages
+		timeout := time.NewTimer(Timeout)
+		defer timeout.Stop()
+		select {
+		case err := <-errCh:
+			log.Fatalf("Error: %v", err)
+		case <-timeout.C:
+			log.Fatalf("Error: timeout waiting for messages in initial subscription")
+		case <-statsCh:
+			// all received
+		}
+
+	}
+
+	// Connect all subscribers (and subscribe to a wildcard topic that includes
+	// all published retained messages).
+	for i := 0; i < nSubscribers; i++ {
+		r := &receiver{
+			clientID:        ClientID + "-sub-" + strconv.Itoa(i),
+			filterPrefix:    messageOpts.topic,
+			topic:           messageOpts.topic + "/+",
+			qos:             messageOpts.qos,
+			expectRetained:  expectRetained,
+			expectPublished: expectPublished,
+			repeat:          repeat,
+		}
+		go r.receive(nil, statsCh, errCh)
+	}
+
+	// wait for the stats
+	total := &Stat{
+		NS: make(map[string]time.Duration),
+	}
+	timeout := time.NewTimer(Timeout)
+	defer timeout.Stop()
+	for i := 0; i < nSubscribers*repeat; i++ {
+		select {
+		case stat := <-statsCh:
+			total.Ops += stat.Ops
+			total.Bytes += stat.Bytes
+			for k, v := range stat.NS {
+				total.NS[k] += v
+			}
+		case err := <-errCh:
+			log.Fatalf("Error: %v", err)
+		case <-timeout.C:
+			log.Fatalf("Error: timeout waiting for messages")
+		}
+	}
+	return total
+}
diff --git a/command-subret.go b/command-subret.go
index 87fe445..9370bf5 100644
--- a/command-subret.go
+++ b/command-subret.go
@@ -27,7 +27,7 @@ type subretCommand struct {
 	// test options
 	repeat      int
 	subscribers int
-	messages      int
+	messages    int
 }
 
 func newSubRetCommand() *cobra.Command {
@@ -51,7 +51,7 @@ func newSubRetCommand() *cobra.Command {
 }
 
 func (c *subretCommand) run(_ *cobra.Command, _ []string) {
-	total := runSubWithPubret(c.subscribers, c.repeat, c.messages, 0, c.messageOpts, true)
+	total := runSubPrepublishRetained(c.subscribers, c.repeat, c.messages, 0, c.messageOpts, true)
 	bb, _ := json.Marshal(total)
 	os.Stdout.Write(bb)
 }
diff --git a/receive.go b/receive.go
index 3d691d0..ae7ecb1 100644
--- a/receive.go
+++ b/receive.go
@@ -18,7 +18,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
-	"strconv"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -124,7 +123,8 @@ func (r *receiver) msgHandler(client paho.Client, msg paho.Message) {
 	default:
 		newC := r.cPublished.Add(1)
 		if newC > int32(r.expectPublished) {
-			r.errCh <- fmt.Errorf("received unexpected published message")
+			r.errCh <- fmt.Errorf("received unexpected published message: dup:%v, topic: %s, qos:%v, retained:%v, payload: %q",
+				msg.Duplicate(), msg.Topic(), msg.Qos(), msg.Retained(), msg.Payload())
 			return
 		}
 
@@ -151,63 +151,3 @@ func (r *receiver) msgHandler(client paho.Client, msg paho.Message) {
 		}
 	}
 }
-
-func runSubWithPubret(
-	nSubscribers int,
-	repeat int,
-	expectRetained,
-	expectPublished int,
-	messageOpts messageOpts,
-	prepublishRetained bool,
-) *Stat {
-	errCh := make(chan error)
-
-	if prepublishRetained {
-		p := &publisher{
-			clientID:    ClientID + "-pub",
-			messages:    expectRetained,
-			topics:      expectRetained,
-			messageOpts: messageOpts,
-		}
-		p.messageOpts.retain = true
-		p.publish(nil, errCh, true)
-	}
-
-	// Connect all subscribers (and subscribe to a wildcard topic that includes
-	// all published retained messages).
-	statsCh := make(chan *Stat)
-	for i := 0; i < nSubscribers; i++ {
-		r := &receiver{
-			clientID:        ClientID + "-sub-" + strconv.Itoa(i),
-			filterPrefix:    messageOpts.topic,
-			topic:           messageOpts.topic + "/+",
-			qos:             messageOpts.qos,
-			expectRetained:  expectRetained,
-			expectPublished: expectPublished,
-			repeat:          repeat,
-		}
-		go r.receive(nil, statsCh, errCh)
-	}
-
-	// wait for the stats
-	total := &Stat{
-		NS: make(map[string]time.Duration),
-	}
-	timeout := time.NewTimer(Timeout)
-	defer timeout.Stop()
-	for i := 0; i < nSubscribers*repeat; i++ {
-		select {
-		case stat := <-statsCh:
-			total.Ops += stat.Ops
-			total.Bytes += stat.Bytes
-			for k, v := range stat.NS {
-				total.NS[k] += v
-			}
-		case err := <-errCh:
-			log.Fatalf("Error: %v", err)
-		case <-timeout.C:
-			log.Fatalf("Error: timeout waiting for messages")
-		}
-	}
-	return total
-}