diff --git a/net/net.go b/net/net.go
index 8654820..f28da84 100644
--- a/net/net.go
+++ b/net/net.go
@@ -357,7 +357,10 @@ func ParseIP(s string) IP {
 
 // String returns the string form of the IP address ip.
 func (ip IP) String() string {
-	return string(ip)
+	if len(ip) < 4 {
+		return ""
+	}
+	return strconv.Itoa(int(ip[0])) + "." + strconv.Itoa(int(ip[1])) + "." + strconv.Itoa(int(ip[2])) + "." + strconv.Itoa(int(ip[3]))
 }
 
 // Conn is a generic stream-oriented network connection.
diff --git a/net/net_test.go b/net/net_test.go
new file mode 100644
index 0000000..e9ac662
--- /dev/null
+++ b/net/net_test.go
@@ -0,0 +1,14 @@
+package net
+
+import (
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+)
+
+func TestIPAddressString(t *testing.T) {
+	c := qt.New(t)
+	ipaddr := ParseIP("127.0.0.1")
+
+	c.Assert(ipaddr.String(), qt.Equals, "127.0.0.1")
+}