diff --git a/u_tls_extensions.go b/u_tls_extensions.go
index 3bc8826d..4d3b07bb 100644
--- a/u_tls_extensions.go
+++ b/u_tls_extensions.go
@@ -1859,6 +1859,9 @@ type FakePreSharedKeyExtension struct {
 }
 
 func (e *FakePreSharedKeyExtension) writeToUConn(uc *UConn) error {
+	if session, ok := uc.config.ClientSessionCache.Get(clientSessionCacheKey(uc.conn.RemoteAddr(), uc.config)); !ok || session == nil {
+		return nil // don't write the extension if there is no session
+	}
 	uc.HandshakeState.Hello.PskIdentities = e.PskIdentities
 	uc.HandshakeState.Hello.PskBinders = e.PskBinders
 	return nil