diff --git a/server/mqtt_test.go b/server/mqtt_test.go
index dd3c55aca7f..b54f31b0812 100644
--- a/server/mqtt_test.go
+++ b/server/mqtt_test.go
@@ -30,7 +30,6 @@ import (
 	"reflect"
 	"runtime"
 	"runtime/pprof"
-	"strconv"
 	"strings"
 	"sync"
 	"testing"
@@ -3070,7 +3069,7 @@ func captureHeapProfile(filename string) {
 func printHeapUsage(label string) runtime.MemStats {
 	var memStats runtime.MemStats
 	runtime.ReadMemStats(&memStats)
-	fmt.Printf("%s Heap: allocs=%v, objects=%v\n", label, memStats.HeapAlloc, memStats.HeapObjects)
+	fmt.Printf("%s Heap: inuse=%v, objects=%v\n", label, memStats.HeapInuse, memStats.HeapObjects)
 	return memStats
 }
 func TestMQTTClusterConnectDisconnectClean(t *testing.T) {
@@ -3100,20 +3099,21 @@ func TestMQTTClusterConnectSubDisconnectClean(t *testing.T) {
 	runtime.GC() // Force garbage collection to get a clear picture
 
 	memStats := printHeapUsage("BEFORE")
-	baseHeapAlloc := memStats.HeapAlloc
+	baseHeapInuse := memStats.HeapInuse
 	baseHeapObjects := memStats.HeapObjects
 
-	for i := 0; i < 10; i++ {
+	N := 1000000
+	for i := 0; i < N; i++ {
 		clientID := nuid.Next()
 		testMQTTConnectSubDisconnect(t, cl.opts[0], clientID, true, false, true, 2)
 		runtime.GC() // Force garbage collection to get a clear picture
 
 		memStats = printHeapUsage(fmt.Sprintf("AFTER %d", i))
-		if memStats.HeapAlloc > 2*baseHeapAlloc || memStats.HeapObjects > 2*baseHeapObjects {
+		if memStats.HeapInuse > 100*baseHeapInuse || memStats.HeapObjects > 100*baseHeapObjects {
 			captureHeapProfile("AFTERLEAK.pprof")
 			t.Fatalf("after %d iterations heap alloc has grown from %v to %v (%v%%), objects from %v to %v (%v%%)",
 				i,
-				sizeKB(baseHeapAlloc), sizeKB(memStats.HeapAlloc), memStats.HeapAlloc*100/baseHeapAlloc,
+				baseHeapInuse, memStats.HeapInuse, memStats.HeapInuse*100/baseHeapInuse,
 				baseHeapObjects, memStats.HeapObjects, memStats.HeapObjects*100/baseHeapObjects)
 		}
 	}