diff --git a/derp/derp.go b/derp/derp.go
index 6a7b3b735..65acd4321 100644
--- a/derp/derp.go
+++ b/derp/derp.go
@@ -18,6 +18,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net"
 	"time"
 )
 
@@ -254,3 +255,14 @@ func writeFrame(bw *bufio.Writer, t frameType, b []byte) error {
 	}
 	return bw.Flush()
 }
+
+// Conn is the subset of the underlying net.Conn the DERP Server needs.
+// It is a defined type so that non-net connections can be used.
+type Conn interface {
+	io.WriteCloser
+	LocalAddr() net.Addr
+	// The *Deadline methods follow the semantics of net.Conn.
+	SetDeadline(time.Time) error
+	SetReadDeadline(time.Time) error
+	SetWriteDeadline(time.Time) error
+}
diff --git a/derp/derp_server.go b/derp/derp_server.go
index 983b5dc00..4b5cc2f78 100644
--- a/derp/derp_server.go
+++ b/derp/derp_server.go
@@ -23,7 +23,6 @@ import (
 	"math"
 	"math/big"
 	"math/rand/v2"
-	"net"
 	"net/http"
 	"net/netip"
 	"os"
@@ -341,17 +340,6 @@ type PacketForwarder interface {
 	String() string
 }
 
-// Conn is the subset of the underlying net.Conn the DERP Server needs.
-// It is a defined type so that non-net connections can be used.
-type Conn interface {
-	io.WriteCloser
-	LocalAddr() net.Addr
-	// The *Deadline methods follow the semantics of net.Conn.
-	SetDeadline(time.Time) error
-	SetReadDeadline(time.Time) error
-	SetWriteDeadline(time.Time) error
-}
-
 var packetsDropped = metrics.NewMultiLabelMap[dropReasonKindLabels](
 	"derp_packets_dropped",
 	"counter",