diff --git a/filter.go b/filter.go
index 8cc2699..3293e56 100644
--- a/filter.go
+++ b/filter.go
@@ -16,21 +16,6 @@ func SubtractFilter(addrs ...ma.Multiaddr) func(ma.Multiaddr) bool {
 	}
 }
 
-// IsFDCostlyTransport returns true for transports that require a new file
-// descriptor per connection created
-func IsFDCostlyTransport(a ma.Multiaddr) bool {
-	res := false
-
-	ma.ForEach(a, func(c ma.Component) bool {
-		if c.Protocol().Code == ma.P_TCP {
-			res = true
-			return false
-		}
-		return true
-	})
-	return res
-}
-
 // FilterNeg returns a negated version of the passed in filter
 func FilterNeg(f func(ma.Multiaddr) bool) func(ma.Multiaddr) bool {
 	return func(a ma.Multiaddr) bool {
diff --git a/filter_test.go b/filter_test.go
index 7229a6b..bf6f993 100644
--- a/filter_test.go
+++ b/filter_test.go
@@ -25,61 +25,3 @@ func TestSubtractAndNegFilter(t *testing.T) {
 		t.Errorf("Expected only one remaining address: %s", localhost.String())
 	}
 }
-
-func TestIsFDCostlyTransport(t *testing.T) {
-	tcpMa := newMultiaddr(t, "/ip4/127.0.0.1/tcp/1234")
-	if ok := IsFDCostlyTransport(tcpMa); !ok {
-		t.Errorf("Expected address %s to need a new file descriptor per new connection", tcpMa.String())
-	}
-	udpMa := newMultiaddr(t, "/ip4/127.0.0.1/udp/1234")
-	if ok := IsFDCostlyTransport(udpMa); ok {
-		t.Errorf("Expected address %s to not need a new file descriptor per new connection", udpMa.String())
-	}
-}
-
-func TestIsFDCostly(t *testing.T) {
-	good := []ma.Multiaddr{
-		newMultiaddr(t, "/ip4/127.0.0.1/tcp/1234"),
-		newMultiaddr(t, "/ip4/0.0.0.0/tcp/1234"),
-		newMultiaddr(t, "/ip6/::1/tcp/1234"),
-		newMultiaddr(t, "/ip6/::/tcp/1234"),
-		newMultiaddr(t, "/ip6/fe80::1/tcp/1234"),
-		newMultiaddr(t, "/ip6/fe80::/tcp/1234"),
-		newMultiaddr(t, "/ip6/fe80::/tcp/1234/http"),
-		newMultiaddr(t, "/ip4/127.0.0.1/tcp/1234/http"),
-	}
-
-	bad := []ma.Multiaddr{
-		newMultiaddr(t, "/ip4/127.0.0.1/udp/1234"),
-		newMultiaddr(t, "/ip4/0.0.0.0/udp/1234/utp"),
-		newMultiaddr(t, "/ip6/::1/udp/1234"),
-		newMultiaddr(t, "/ip6/::/udp/1234"),
-	}
-
-	for _, a := range bad {
-		if IsFDCostlyTransport(a) {
-			t.Errorf("addr %s should not be fd costly", a)
-		}
-	}
-
-	for _, a := range good {
-		if !IsFDCostlyTransport(a) {
-			t.Errorf("addr %s should be fd costly", a)
-		}
-	}
-}
-
-func TestIsFdCostlyMalformed(t *testing.T) {
-	bad := []ma.Multiaddr{
-		newMultiaddr(t, "/ip4/127.0.0.1/"),
-		newMultiaddr(t, "/ip4/0.0.0.0/"),
-		newMultiaddr(t, "/ip6/::1/"),
-		newMultiaddr(t, "/ip6/::/"),
-	}
-
-	for _, a := range bad {
-		if IsFDCostlyTransport(a) {
-			t.Errorf("addr %s should not be fd costly", a)
-		}
-	}
-}