diff --git a/client_test.go b/client_test.go
index 4ddd37f7..eb980576 100644
--- a/client_test.go
+++ b/client_test.go
@@ -161,8 +161,8 @@ func TestClientEDNS0Local(t *testing.T) {
 	}
 }
 
-// ExampleUpdateLeaseTSIG shows how to update a lease signed with TSIG.
-func ExampleUpdateLeaseTSIG(t *testing.T) {
+// ExampleTsigSecret_updateLeaseTSIG shows how to update a lease signed with TSIG
+func ExampleTsigSecret_updateLeaseTSIG() {
 	m := new(Msg)
 	m.SetUpdate("t.local.ip6.io.")
 	rr, _ := NewRR("t.local.ip6.io. 30 A 127.0.0.1")
@@ -185,7 +185,7 @@ func ExampleUpdateLeaseTSIG(t *testing.T) {
 
 	_, _, err := c.Exchange(m, "127.0.0.1:53")
 	if err != nil {
-		t.Error(err)
+		panic(err)
 	}
 }
 
diff --git a/example_test.go b/example_test.go
index 1578a4d0..64c14962 100644
--- a/example_test.go
+++ b/example_test.go
@@ -3,9 +3,10 @@ package dns_test
 import (
 	"errors"
 	"fmt"
-	"github.com/miekg/dns"
 	"log"
 	"net"
+
+	"github.com/miekg/dns"
 )
 
 // Retrieve the MX records for miek.nl.
@@ -31,13 +32,11 @@ func ExampleMX() {
 
 // Retrieve the DNSKEY records of a zone and convert them
 // to DS records for SHA1, SHA256 and SHA384.
-func ExampleDS(zone string) {
+func ExampleDS() {
 	config, _ := dns.ClientConfigFromFile("/etc/resolv.conf")
 	c := new(dns.Client)
 	m := new(dns.Msg)
-	if zone == "" {
-		zone = "miek.nl"
-	}
+	zone := "miek.nl"
 	m.SetQuestion(dns.Fqdn(zone), dns.TypeDNSKEY)
 	m.SetEdns0(4096, true)
 	r, _, err := c.Exchange(m, config.Servers[0]+":"+config.Port)
diff --git a/idn/punycode.go b/idn/punycode.go
index d3433fbd..7e5c263f 100644
--- a/idn/punycode.go
+++ b/idn/punycode.go
@@ -199,7 +199,6 @@ func needFromPunycode(s string) bool {
 			return true
 		}
 	}
-	panic("dns: not reached")
 }
 
 // encode transforms Unicode input bytes (that represent DNS label) into
diff --git a/parse_test.go b/parse_test.go
index 1bf4d871..f2922e0b 100644
--- a/parse_test.go
+++ b/parse_test.go
@@ -569,7 +569,7 @@ test                          IN CNAME test.a.example.com.
 	t.Logf("%d RRs parsed in %.2f s (%.2f RR/s)", i, float32(delta)/1e9, float32(i)/(float32(delta)/1e9))
 }
 
-func ExampleZone() {
+func ExampleParseZone() {
 	zone := `$ORIGIN .
 $TTL 3600       ; 1 hour
 name                    IN SOA  a6.nstld.com. hostmaster.nic.name. (
@@ -799,7 +799,7 @@ func TestLowercaseTokens(t *testing.T) {
 	}
 }
 
-func ExampleGenerate() {
+func ExampleParseZone_generate() {
 	// From the manual: http://www.bind9.net/manual/bind/9.3.2/Bv9ARM.ch06.html#id2566761
 	zone := "$GENERATE 1-2 0 NS SERVER$.EXAMPLE.\n$GENERATE 1-8 $ CNAME $.0"
 	to := ParseZone(strings.NewReader(zone), "0.0.192.IN-ADDR.ARPA.", "")