diff --git a/inet.go b/inet.go
index f35f88ba..25e56170 100644
--- a/inet.go
+++ b/inet.go
@@ -47,17 +47,26 @@ func (dst *Inet) Set(src interface{}) error {
 	case string:
 		ip, ipnet, err := net.ParseCIDR(value)
 		if err != nil {
-			ip = net.ParseIP(value)
+			ip := net.ParseIP(value)
 			if ip == nil {
 				return fmt.Errorf("unable to parse inet address: %s", value)
 			}
-			ipnet = &net.IPNet{IP: ip, Mask: net.CIDRMask(128, 128)}
+
 			if ipv4 := ip.To4(); ipv4 != nil {
-				ip = ipv4
-				ipnet.Mask = net.CIDRMask(32, 32)
+				ipnet = &net.IPNet{IP: ipv4, Mask: net.CIDRMask(32, 32)}
+			} else {
+				ipnet = &net.IPNet{IP: ip, Mask: net.CIDRMask(128, 128)}
+			}
+		} else {
+			ipnet.IP = ip
+			if ipv4 := ipnet.IP.To4(); ipv4 != nil {
+				ipnet.IP = ipv4
+				if len(ipnet.Mask) == 16 {
+					ipnet.Mask = ipnet.Mask[12:] // Needed if input is IPv4-mapped IPv6.
+				}
 			}
 		}
-		ipnet.IP = ip
+
 		*dst = Inet{IPNet: ipnet, Status: Present}
 	case *net.IPNet:
 		if value == nil {
diff --git a/inet_test.go b/inet_test.go
index 8d70c0d0..badbf82e 100644
--- a/inet_test.go
+++ b/inet_test.go
@@ -52,10 +52,12 @@ func TestInetSet(t *testing.T) {
 		{source: mustParseCIDR(t, "127.0.0.1/32"), result: pgtype.Inet{IPNet: mustParseCIDR(t, "127.0.0.1/32"), Status: pgtype.Present}},
 		{source: mustParseCIDR(t, "127.0.0.1/32").IP, result: pgtype.Inet{IPNet: mustParseCIDR(t, "127.0.0.1/32"), Status: pgtype.Present}},
 		{source: "127.0.0.1/32", result: pgtype.Inet{IPNet: mustParseCIDR(t, "127.0.0.1/32"), Status: pgtype.Present}},
-		{source: "1.2.3.4/24", result: pgtype.Inet{IPNet: &net.IPNet{IP: net.ParseIP("1.2.3.4"), Mask: net.CIDRMask(24, 32)}, Status: pgtype.Present}},
+		{source: "1.2.3.4/24", result: pgtype.Inet{IPNet: &net.IPNet{IP: net.ParseIP("1.2.3.4").To4(), Mask: net.CIDRMask(24, 32)}, Status: pgtype.Present}},
 		{source: "10.0.0.1", result: pgtype.Inet{IPNet: mustParseInet(t, "10.0.0.1"), Status: pgtype.Present}},
 		{source: "2607:f8b0:4009:80b::200e", result: pgtype.Inet{IPNet: mustParseInet(t, "2607:f8b0:4009:80b::200e"), Status: pgtype.Present}},
 		{source: net.ParseIP(""), result: pgtype.Inet{Status: pgtype.Null}},
+		{source: "0.0.0.0/8", result: pgtype.Inet{IPNet: mustParseInet(t, "0.0.0.0/8"), Status: pgtype.Present}},
+		{source: "::ffff:0.0.0.0/104", result: pgtype.Inet{IPNet: &net.IPNet{IP: net.ParseIP("0.0.0.0").To4(), Mask: net.CIDRMask(8, 32)}, Status: pgtype.Present}},
 	}
 
 	for i, tt := range successfulTests {
@@ -70,6 +72,7 @@ func TestInetSet(t *testing.T) {
 		if tt.result.Status == pgtype.Present {
 			assert.Equalf(t, tt.result.IPNet.Mask, r.IPNet.Mask, "%d: Mask", i)
 			assert.Truef(t, tt.result.IPNet.IP.Equal(r.IPNet.IP), "%d: IP", i)
+			assert.Equalf(t, len(tt.result.IPNet.IP), len(r.IPNet.IP), "%d: IP length", i)
 		}
 	}
 }