diff --git a/doq.go b/doq.go
index f0a7bc1..365fa10 100644
--- a/doq.go
+++ b/doq.go
@@ -23,7 +23,7 @@ func (r *doqResolver) Resolve(ctx context.Context, msg *dns.Msg) (*dns.Msg, erro
 	ip := r.uc.BootstrapIP
 	if ip == "" {
 		dnsTyp := uint16(0)
-		if len(msg.Question) > 0 {
+		if msg != nil && len(msg.Question) > 0 {
 			dnsTyp = msg.Question[0].Qtype
 		}
 		ip = r.uc.bootstrapIPForDNSType(dnsTyp)
diff --git a/dot.go b/dot.go
index 2e11a8f..68cf2e1 100644
--- a/dot.go
+++ b/dot.go
@@ -20,7 +20,7 @@ func (r *dotResolver) Resolve(ctx context.Context, msg *dns.Msg) (*dns.Msg, erro
 	// regardless of the machine DNS status.
 	dialer := newDialer(net.JoinHostPort(bootstrapDNS, "53"))
 	dnsTyp := uint16(0)
-	if len(msg.Question) > 0 {
+	if msg != nil && len(msg.Question) > 0 {
 		dnsTyp = msg.Question[0].Qtype
 	}
 
diff --git a/resolver.go b/resolver.go
index 89b98b6..1e07c78 100644
--- a/resolver.go
+++ b/resolver.go
@@ -117,7 +117,7 @@ func (r *legacyResolver) Resolve(ctx context.Context, msg *dns.Msg) (*dns.Msg, e
 	// See comment in (*dotResolver).resolve method.
 	dialer := newDialer(net.JoinHostPort(bootstrapDNS, "53"))
 	dnsTyp := uint16(0)
-	if len(msg.Question) > 0 {
+	if msg != nil && len(msg.Question) > 0 {
 		dnsTyp = msg.Question[0].Qtype
 	}
 	_, udpNet := r.uc.netForDNSType(dnsTyp)