diff --git a/cache.go b/cache.go
index 2dd7e4b..c390ed9 100644
--- a/cache.go
+++ b/cache.go
@@ -101,7 +101,7 @@ func (c *cache) get(qname string) RRs {
 		rrs := make(RRs, len(e))
 		now := time.Now()
 		for rr, _ := range e {
-			if rr.Expiry != nil && now.After(*rr.Expiry) {
+			if rr.Expiry != emptyTime && now.After(rr.Expiry) {
 				delete(e, rr)
 			} else {
 				rrs[i] = rr
diff --git a/cache_test.go b/cache_test.go
index 0d13dd5..f5d39c5 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -20,7 +20,7 @@ func TestLiveCacheEntry(t *testing.T) {
 	c := newCache(100, true)
 	c.addNX("alive.")
 	alive := time.Now().Add(time.Minute)
-	rr := RR{Name: "alive.", Type: "A", Value: "1.2.3.4", Expiry: &alive}
+	rr := RR{Name: "alive.", Type: "A", Value: "1.2.3.4", Expiry: alive}
 	c.add("alive.", rr)
 	rrs := c.get("alive.")
 	st.Expect(t, len(rrs), 1)
@@ -30,7 +30,7 @@ func TestExpiredCacheEntry(t *testing.T) {
 	c := newCache(100, true)
 	c.addNX("expired.")
 	expired := time.Now().Add(-time.Minute)
-	rr := RR{Name: "expired.", Type: "A", Value: "1.2.3.4", Expiry: &expired}
+	rr := RR{Name: "expired.", Type: "A", Value: "1.2.3.4", Expiry: expired}
 	c.add("expired.", rr)
 	rrs := c.get("expired.")
 	st.Expect(t, len(rrs), 0)
diff --git a/resolver_test.go b/resolver_test.go
index bf30ae8..2256a5b 100644
--- a/resolver_test.go
+++ b/resolver_test.go
@@ -193,7 +193,7 @@ func TestTTL(t *testing.T) {
 	st.Expect(t, err, nil)
 	st.Expect(t, len(rrs) >= 4, true)
 	rr := rrs[0]
-	st.Expect(t, rr.Expiry != nil, true)
+	st.Expect(t, rr.Expiry != emptyTime, true)
 }
 
 var testResolver *Resolver
diff --git a/rr.go b/rr.go
index ff326e9..75ea5b4 100644
--- a/rr.go
+++ b/rr.go
@@ -13,8 +13,8 @@ type RR struct {
 	Name   string
 	Type   string
 	Value  string
-	TTL    *time.Duration
-	Expiry *time.Time
+	TTL    time.Duration
+	Expiry time.Time
 }
 
 // RRs represents a slice of DNS resource records.
@@ -24,6 +24,9 @@ type RRs []RR
 // It is used to save allocations at runtime.
 var emptyRRs = RRs{}
 
+// emptyTime is used to detect an empty expiry time.
+var emptyTime = time.Time{}
+
 // ICANN specifies that DNS servers should return the special value 127.0.53.53
 // for A record queries of TLDs that have recently entered the root zone,
 // that have a high likelyhood of colliding with private DNS names.
@@ -34,7 +37,7 @@ const NameCollision = "127.0.53.53"
 
 // String returns a string representation of an RR in zone-file format.
 func (rr *RR) String() string {
-	if rr.TTL == nil {
+	if rr.Expiry == emptyTime {
 		return rr.Name + "\t      3600\tIN\t" + rr.Type + "\t" + rr.Value
 	} else {
 		ttl := ttlString(rr.TTL)
@@ -43,7 +46,7 @@ func (rr *RR) String() string {
 }
 
 // ttlString constructs the TTL field of an RR string.
-func ttlString(ttl *time.Duration) string {
+func ttlString(ttl time.Duration) string {
 	seconds := int(ttl.Seconds())
 	return fmt.Sprintf("%10d", seconds)
 }
@@ -53,8 +56,8 @@ func ttlString(ttl *time.Duration) string {
 // It will attempt to translate this if there are enough parameters
 // Should all translation fail, it returns an undefined RR and false.
 func convertRR(drr dns.RR, expire bool) (RR, bool) {
-	var ttl *time.Duration
-	var expiry *time.Time
+	var ttl time.Duration
+	var expiry time.Time
 	if expire {
 		ttl, expiry = calculateExpiry(drr)
 	}
@@ -81,8 +84,8 @@ func convertRR(drr dns.RR, expire bool) (RR, bool) {
 }
 
 // calculateExpiry calculates the expiry time of an RR.
-func calculateExpiry(drr dns.RR) (*time.Duration, *time.Time) {
+func calculateExpiry(drr dns.RR) (time.Duration, time.Time) {
 	ttl := time.Second * time.Duration(drr.Header().Ttl)
 	expiry := time.Now().Add(ttl)
-	return &ttl, &expiry
+	return ttl, expiry
 }