diff --git a/src/net/dnsclient.go b/src/net/dnsclient.go
index e8014e4ffc..56e2a94965 100644
--- a/src/net/dnsclient.go
+++ b/src/net/dnsclient.go
@@ -43,8 +43,8 @@ func reverseaddr(addr string) (arpa string, err error) {
 		return "", &DNSError{Err: "unrecognized address", Name: addr}
 	}
 	if ip.To4() != nil {
-		return itoa(int(ip[15])) + "." + itoa(int(ip[14])) + "." + itoa(int(ip[13])) + "." +
-			itoa(int(ip[12])) + ".in-addr.arpa.", nil
+		return uitoa(uint(ip[15])) + "." + uitoa(uint(ip[14])) + "." + uitoa(uint(ip[13])) + "." +
+			uitoa(uint(ip[12])) + ".in-addr.arpa.", nil
 	}
 	// Must be IPv6
 	buf := make([]byte, 0, len(ip)*4+len("ip6.arpa."))
diff --git a/src/net/ip.go b/src/net/ip.go
index 4a93e97b39..7bcc40e8f6 100644
--- a/src/net/ip.go
+++ b/src/net/ip.go
@@ -267,10 +267,10 @@ func (ip IP) String() string {
 
 	// If IPv4, use dotted notation.
 	if p4 := p.To4(); len(p4) == IPv4len {
-		return itod(uint(p4[0])) + "." +
-			itod(uint(p4[1])) + "." +
-			itod(uint(p4[2])) + "." +
-			itod(uint(p4[3]))
+		return uitoa(uint(p4[0])) + "." +
+			uitoa(uint(p4[1])) + "." +
+			uitoa(uint(p4[2])) + "." +
+			uitoa(uint(p4[3]))
 	}
 	if len(p) != IPv6len {
 		return "?"
@@ -491,7 +491,7 @@ func (n *IPNet) String() string {
 	if l == -1 {
 		return nn.String() + "/" + m.String()
 	}
-	return nn.String() + "/" + itod(uint(l))
+	return nn.String() + "/" + uitoa(uint(l))
 }
 
 // Parse IPv4 address (d.d.d.d).
diff --git a/src/net/ipsock.go b/src/net/ipsock.go
index dda8578030..858c6ef12c 100644
--- a/src/net/ipsock.go
+++ b/src/net/ipsock.go
@@ -303,7 +303,7 @@ func zoneToString(zone int) string {
 	if ifi, err := InterfaceByIndex(zone); err == nil {
 		return ifi.Name
 	}
-	return itod(uint(zone))
+	return uitoa(uint(zone))
 }
 
 func zoneToInt(zone string) int {
diff --git a/src/net/parse.go b/src/net/parse.go
index e1d0130c9a..ad901fff27 100644
--- a/src/net/parse.go
+++ b/src/net/parse.go
@@ -171,43 +171,30 @@ func xtoi2(s string, e byte) (byte, bool) {
 	return byte(n), ok && ei == 2
 }
 
-// Integer to decimal.
-func itoa(i int) string {
-	var buf [30]byte
-	n := len(buf)
-	neg := false
-	if i < 0 {
-		i = -i
-		neg = true
+// Convert integer to decimal string.
+func itoa(val int) string {
+	if val < 0 {
+		return "-" + uitoa(uint(-val))
 	}
-	ui := uint(i)
-	for ui > 0 || n == len(buf) {
-		n--
-		buf[n] = byte('0' + ui%10)
-		ui /= 10
-	}
-	if neg {
-		n--
-		buf[n] = '-'
-	}
-	return string(buf[n:])
+	return uitoa(uint(val))
 }
 
-// Convert i to decimal string.
-func itod(i uint) string {
-	if i == 0 {
+// Convert unsigned integer to decimal string.
+func uitoa(val uint) string {
+	if val == 0 { // avoid string allocation
 		return "0"
 	}
-
-	// Assemble decimal in reverse order.
-	var b [32]byte
-	bp := len(b)
-	for ; i > 0; i /= 10 {
-		bp--
-		b[bp] = byte(i%10) + '0'
+	var buf [20]byte // big enough for 64bit value base 10
+	i := len(buf) - 1
+	for val >= 10 {
+		q := val / 10
+		buf[i] = byte('0' + val - q*10)
+		i--
+		val = q
 	}
-
-	return string(b[bp:])
+	// val < 10
+	buf[i] = byte('0' + val)
+	return string(buf[i:])
 }
 
 // Convert i to a hexadecimal string. Leading zeros are not printed.