diff --git a/go.mod b/go.mod
index 1a445760..77092423 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,7 @@ go 1.13
 require (
 	github.com/agext/levenshtein v1.2.2 // indirect
 	github.com/apparentlymart/go-textseg v1.0.0
-	github.com/creachadair/jrpc2 v0.17.0
+	github.com/creachadair/jrpc2 v0.18.0
 	github.com/fsnotify/fsnotify v1.4.9
 	github.com/google/go-cmp v0.5.6
 	github.com/google/uuid v1.2.0 // indirect
diff --git a/go.sum b/go.sum
index a89e43f8..40cebf81 100644
--- a/go.sum
+++ b/go.sum
@@ -73,8 +73,8 @@ github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3Ee
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
-github.com/creachadair/jrpc2 v0.17.0 h1:F+wTIeYVndkoE6CC9ikJN/jtw17AbbskSLD+MZf2ArI=
-github.com/creachadair/jrpc2 v0.17.0/go.mod h1:gaeysmTjY/kHSaCEjxF1pHXl8bc0X5otQPnQiA6r9Xk=
+github.com/creachadair/jrpc2 v0.18.0 h1:eri9qZeiVwPSVTLqUk0MYixlzdBMdaEBi9AgrihuGIA=
+github.com/creachadair/jrpc2 v0.18.0/go.mod h1:gaeysmTjY/kHSaCEjxF1pHXl8bc0X5otQPnQiA6r9Xk=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
diff --git a/internal/langserver/handlers/service.go b/internal/langserver/handlers/service.go
index 2d4d1828..16d5883b 100644
--- a/internal/langserver/handlers/service.go
+++ b/internal/langserver/handlers/service.go
@@ -416,7 +416,7 @@ func (svc *service) Assigner() (jrpc2.Assigner, error) {
 	return convertMap(m), nil
 }
 
-func (svc *service) Finish(status jrpc2.ServerStatus) {
+func (svc *service) Finish(_ jrpc2.Assigner, status jrpc2.ServerStatus) {
 	if status.Closed() || status.Err != nil {
 		svc.logger.Printf("session stopped unexpectedly (err: %v)", status.Err)
 	}
diff --git a/internal/langserver/langserver.go b/internal/langserver/langserver.go
index 545688a5..b89b8657 100644
--- a/internal/langserver/langserver.go
+++ b/internal/langserver/langserver.go
@@ -160,8 +160,10 @@ func Server(svc server.Service, opts *jrpc2.ServerOptions) (*singleServer, error
 	}
 
 	return &singleServer{
-		srv:        jrpc2.NewServer(assigner, opts),
-		finishFunc: svc.Finish,
+		srv: jrpc2.NewServer(assigner, opts),
+		finishFunc: func(status jrpc2.ServerStatus) {
+			svc.Finish(assigner, status)
+		},
 	}, nil
 }
 
diff --git a/internal/langserver/session/types.go b/internal/langserver/session/types.go
index 8e25ea1d..7575676d 100644
--- a/internal/langserver/session/types.go
+++ b/internal/langserver/session/types.go
@@ -9,7 +9,7 @@ import (
 
 type Session interface {
 	Assigner() (jrpc2.Assigner, error)
-	Finish(jrpc2.ServerStatus)
+	Finish(jrpc2.Assigner, jrpc2.ServerStatus)
 	SetLogger(*log.Logger)
 }