diff --git a/server/client.go b/server/client.go
index 8c023b86..e7080f82 100644
--- a/server/client.go
+++ b/server/client.go
@@ -1035,6 +1035,10 @@ func (c *client) flushOutbound() bool {
 
 	// For selecting primary replacement.
 	cnb := nb
+	var lfs int
+	if len(cnb) > 0 {
+		lfs = len(cnb[0])
+	}
 
 	// In case it goes away after releasing the lock.
 	nc := c.nc
@@ -1112,7 +1116,7 @@ func (c *client) flushOutbound() bool {
 	}
 
 	// Check to see if we can reuse buffers.
-	if len(cnb) > 0 && n >= int64(len(cnb[0])) {
+	if lfs != 0 && n >= int64(lfs) {
 		oldp := cnb[0][:0]
 		if cap(oldp) >= int(c.out.sz) {
 			// Replace primary or secondary if they are nil, reusing same buffer.
diff --git a/server/client_test.go b/server/client_test.go
index 449d21b1..9a5ddc1d 100644
--- a/server/client_test.go
+++ b/server/client_test.go
@@ -1943,7 +1943,7 @@ type testConnWritePartial struct {
 func (c *testConnWritePartial) Write(p []byte) (int, error) {
 	n := len(p)
 	if c.partial {
-		n = 5
+		n = 15
 	}
 	return c.buf.Write(p[:n])
 }
@@ -1957,7 +1957,7 @@ func TestFlushOutboundNoSliceReuseIfPartial(t *testing.T) {
 	opts.MaxPending = 1024
 	s := &Server{opts: opts}
 
-	fakeConn := &testConnWritePartial{}
+	fakeConn := &testConnWritePartial{partial: true}
 	c := &client{srv: s, nc: fakeConn}
 	c.initClient()
 
@@ -1967,18 +1967,13 @@ func TestFlushOutboundNoSliceReuseIfPartial(t *testing.T) {
 		[]byte("0123456789"),
 	}
 	expected := bytes.Buffer{}
-	for i, buf := range bufs {
+	for _, buf := range bufs {
 		expected.Write(buf)
 		c.mu.Lock()
-		if i == 0 {
-			fakeConn.partial = true
-			c.out.sz = 10
-		} else {
-			fakeConn.partial = false
-			c.out.sz = 5
-		}
 		c.queueOutbound(buf)
+		c.out.sz = 10
 		c.flushOutbound()
+		fakeConn.partial = false
 		c.mu.Unlock()
 	}
 	// Ensure everything is flushed.