diff --git a/ssh/common.go b/ssh/common.go
index 4024712..aed0fd9 100644
--- a/ssh/common.go
+++ b/ssh/common.go
@@ -544,7 +544,7 @@ func (c *Config) SetDefaults() {
 	if c.Rand == nil {
 		c.Rand = rand.Reader
 	}
-	if c.Ciphers == nil {
+	if len(c.Ciphers) == 0 {
 		c.Ciphers = defaultCiphers
 	}
 	var ciphers []string
@@ -556,7 +556,7 @@ func (c *Config) SetDefaults() {
 	}
 	c.Ciphers = ciphers
 
-	if c.KeyExchanges == nil {
+	if len(c.KeyExchanges) == 0 {
 		c.KeyExchanges = defaultKexAlgos
 	}
 	var kexs []string
@@ -571,7 +571,7 @@ func (c *Config) SetDefaults() {
 	}
 	c.KeyExchanges = kexs
 
-	if c.MACs == nil {
+	if len(c.MACs) == 0 {
 		c.MACs = defaultMACs
 	}
 	var macs []string
diff --git a/ssh/handshake.go b/ssh/handshake.go
index 4be3cbb..711a7f7 100644
--- a/ssh/handshake.go
+++ b/ssh/handshake.go
@@ -162,7 +162,7 @@ func newClientTransport(conn keyingTransport, clientVersion, serverVersion []byt
 	t.remoteAddr = addr
 	t.hostKeyCallback = config.HostKeyCallback
 	t.bannerCallback = config.BannerCallback
-	if config.HostKeyAlgorithms != nil {
+	if len(config.HostKeyAlgorithms) > 0 {
 		t.hostKeyAlgorithms = config.HostKeyAlgorithms
 	} else {
 		t.hostKeyAlgorithms = defaultHostKeyAlgos