diff --git a/wgengine/magicsock/magicsock.go b/wgengine/magicsock/magicsock.go
index 67314c700..f111e5581 100644
--- a/wgengine/magicsock/magicsock.go
+++ b/wgengine/magicsock/magicsock.go
@@ -2259,13 +2259,6 @@ func (c *Conn) Close() error {
 	return err
 }
 
-// isClosed reports whether c is closed.
-func (c *Conn) isClosed() bool {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.closed
-}
-
 func (c *Conn) goroutinesRunningLocked() bool {
 	if c.endpointsUpdateActive {
 		return true
@@ -2997,10 +2990,6 @@ func (de *discoEndpoint) heartbeat() {
 
 	de.heartBeatTimer = nil
 
-	if de.c.isClosed() {
-		return
-	}
-
 	if de.lastSend.IsZero() {
 		// Shouldn't happen.
 		return